Cancer treatment methods using selected immunoconjugates for binding to aminophospholipids

ABSTRACT

Disclosed are surprising discoveries concerning the role of anionic phospholipids and aminophospholipids in tumor vasculature and in viral entry and spread, and compositions and methods for utilizing these findings in the treatment of cancer and viral infections. Also disclosed are advantageous antibody, immunoconjugate and duramycin-based compositions and combinations that bind and inhibit anionic phospholipids and aminophospholipids, for use in the safe and effective treatment of cancer, viral infections and related diseases.

The present application is a continuation-in-part that claims priorityto U.S. application Ser. No. 10/621,269, filed Jul. 15, 2003, whichclaims priority to U.S. provisional application Ser. No. 60/396,263,filed Jul. 15, 2002, the disclosures of which applications, includingthe specification, claims, drawings and sequences, are specificallyincorporated herein by reference without disclaimer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the fields of aminophospholipid andanionic phospholipid biology, tumor blood vessels and viral infections.It provides surprising new compositions, methods and combinations fortumor vasculature targeting and cancer treatment, for inhibiting viralentry and spread and for treating viral infections. The inventionfurther provides a number of preferred antibody, immunoconjugate andduramycin-based compositions that bind and inhibit aminophospholipidsand anionic phospholipids for use in the treatment of cancer, viralinfections and related diseases.

2. Description of the Related Art

Tumor cell resistance to chemotherapeutic agents represents asignificant problem in clinical oncology. Another major problem toaddress in tumor treatment is the desire for a “total cell kill”, i.e.,killing all so-called “clonogenic” malignant cells that have the abilityto grow uncontrolled and replace any tumor mass that might be removed bythe therapy. Despite certain advances in the field, these are two of themain reasons why many prevalent forms of human cancer still resisteffective chemotherapeutic intervention.

Due to the goal of developing treatments that approach a total cellkill, certain types of tumors have been more amenable to therapy thanothers. For example, the soft tissue tumors, e.g., lymphomas, and tumorsof the blood and blood-forming organs, e.g., leukemias, have generallybeen more responsive to chemotherapeutic therapy than have solid tumors,such as carcinomas.

One reason for the susceptibility of soft and blood-based tumors tochemotherapy is the greater accessibility of lymphoma and leukemic cellsto chemotherapeutic intervention. Simply put, it is much more difficultfor most chemotherapeutic agents to reach all of the cells of a solidtumor mass than it is the soft tumors and blood-based tumors, andtherefore much more difficult to achieve a total cell kill. Increasingthe dose of chemotherapeutic agents most often results in toxic sideeffects, which generally limits the effectiveness of conventionalanti-tumor agents.

Another tumor treatment strategy is the use of an “immunotoxin”, inwhich an anti-tumor cell antibody is used to deliver a toxin to thetumor cells. However, in common with chemotherapeutic approaches,immunotoxin therapy also suffers from significant drawbacks when appliedto solid tumors. For example, antigen-negative or antigen-deficientcells can survive and repopulate the tumor or lead to furthermetastases. A further reason for solid tumor resistance toantibody-based therapies is that the tumor mass is generally impermeableto macromolecular agents such as antibodies and immunotoxins. Both thephysical diffusion distances and the interstitial pressure within thetumor are significant limitations to this type of therapy.

An improved treatment strategy is to target the vasculature of solidtumors. Targeting the blood vessels of the tumors, rather than the tumorcells themselves, has certain advantages in that it is not likely tolead to the development of resistant tumor cells, and that the targetedcells are readily accessible. Moreover, destruction of the blood vesselsleads to an amplification of the anti-tumor effect, as many tumor cellsrely on a single vessel for their oxygen and nutrients. Exemplaryvascular targeting agents (VTAs) are described in U.S. Pat. Nos.5,855,866, 5,965,132, 6,261,535, 6,051,230 and 6,451,312, which describethe targeted delivery of anti-cellular agents and toxins to markers oftumor vasculature.

Another effective version of the vascular targeting approach is totarget a coagulation factor to a marker expressed or adsorbed within thetumor vasculature or stroma (Huang et al., 1997; U.S. Pat. Nos.6,093,399, 6,004,555, 5,877,289, and 6,036,955). The delivery ofcoagulants, rather than toxins, to tumor vasculature has the furtheradvantages of reduced immunogenicity and even lower risk of toxic sideeffects. As disclosed in U.S. Pat. No. 5,877,289, a preferredcoagulation factor for use in such tumor-specific “coaguligands” is atruncated version of the human coagulation-inducing protein, TissueFactor (TF), the major initiator of blood coagulation.

Recently, the aminophospholipids phosphatidylserine (PS) andphosphatidylethanolamine (PE) were identified as specific markers oftumor vasculature (Ran et al., 1998). This led to the development of newanti-PS and anti-PE immunoconjugates for delivering anti-cellularagents, toxins and coagulation factors to tumor blood vessels (U.S. Pat.No. 6,312,694). In addition, it was discovered that unconjugatedantibodies to PS and PE exerted an anti-cancer effect without attachmentto a therapeutic agent, which became known as the aminophospholipid“naked antibody” approach to tumor vascular targeting and treatment(U.S. Pat. No. 6,406,693).

Although the foregoing immunoconjugate and aminophospholipid vasculartargeting methods represent significant advances in tumor treatment,certain peripheral tumor cells can survive the widespread tumordestruction caused by such therapies. Anti-angiogenic strategies, whichinhibit the development of new vasculature from preexisting bloodvessels and/or circulating endothelial stem cells, are thereforecontemplated for use in combination with the VTA, coaguligand andaminophospholipid targeting methods of U.S. Pat. Nos. 5,855,866,6,093,399, 6,312,694 and 6,406,693.

Angiogenesis plays an important role in physiological processes, such asembryogenesis, wound healing and menstruation, but is also involved incertain pathological events, such as in tumor growth, arthritis,psoriasis and diabetic retinopathy (Ferrara, 1995). As applied to tumortreatment, anti-angiogenic strategies are based upon inhibiting theproliferation of budding vessels, generally at the periphery of a solidtumor. These therapies are mostly applied to reduce the risk ofmicrometastasis or to inhibit further growth of a solid tumor after moreconventional intervention (such as surgery or chemotherapy).

U.S. Pat. Nos. 6,342,219, 6,524,583, 6,342,221 and 6,416,758 describeantibodies and immunoconjugates that bind to vascular endothelial growthfactor-A (VEGF, formerly known as vascular permeability factor, VPF), aprimary stimulant of angiogenesis. These antibodies have the importantadvantage of inhibiting VEGF binding to only one of the two primary VEGFreceptors. By blocking VEGF binding to VEGFR2, but not VEGFR1, theseantibodies have an improved safety profile, maintaining beneficialeffects mediated via VEGFR1, e.g. in macrophage, osteoclast andchondroclast functions.

Although the foregoing methods have advanced the art of tumor treatment,the development of additional or alternative vascular targetingtherapies is still sought. The identification of new markers of tumorvasculature is needed to expand the number of therapeutic options. Thedevelopment of new naked antibodies with anti-cancer properties would bea particularly important advance, as this permits the same targetingmoiety to be used both as a single-agent therapeutic and as a vasculartargeting agent for the delivery of other drugs. Therapeutic agents thathave both anti-angiogenic and anti-vascular, i.e., tumor destructive,properties within the same molecule would be of great value. An evenmore important advance would be the identification of a class oftherapeutic agents with anti-cancer properties and therapeutic effectsin other systems. The development of agents capable of treating bothcancer and viral infections, two of the most significant medicalchallenges of this era, would be a remarkable and importantbreakthrough.

SUMMARY OF THE INVENTION

The present invention addresses the foregoing and other needs of theprior art by providing new methods and compositions for safe andeffective tumor vascular targeting, anti-angiogenesis and tumordestruction, which methods and compositions are also surprisinglyeffective in inhibiting viral entry, replication and spread and fortreating viral infections and diseases. The invention is based, in part,on surprising discoveries concerning the expression and role of anionicphospholipids in tumor vasculature and the involvement ofaminophospholipids and anionic phospholipids in viral entry, replicationand spread. The present invention further provides particularlyadvantageous antibodies and immunoconjugates that bind toaminophospholipids and anionic phospholipids, and a new class ofpeptide-based derivatives that bind to phosphatidylethanolamine.

Overview: In a first overall embodiment, the invention provides newmethods for tumor vascular targeting, tumor imaging and treatment basedupon the unexpected finding that anionic phospholipids, such asphosphatidylinositol (PI), phosphatidic acid (PA) andphosphatidylglycerol (PG), (as well as phosphatidylserine, PS), areaccessible and stably targetable markers of tumor vasculature. Thisembodiment arose from the unexpected discovery that antibodies againstPA, PI, PG, and other anionic phospholipid components, specificallylocalize to the vasculature of solid tumors.

Further aspects within this embodiment were developed from theunexpected discovery that naked antibodies against anionicphospholipids, such as PA, PI and PG (as well as PS), specificallyinhibit tumor blood vessel angiogenesis and induce tumor vasculaturedestruction and tumor necrosis in vivo in the absence of conjugation toeffector molecules, such as toxins or coagulants. The invention thusprovides safe and effective methods of vascular targeting,anti-angiogenesis and tumor treatment using single componentantibody-based therapeutics that bind to anionic phospholipids.

An underlying surprising feature of the invention is that translocationof anionic phospholipids to the surface of tumor vascular endothelialcells occurs, at least in a significant part, independently of celldamage and apoptotic or other cell-death mechanisms. Anionicphospholipid expression in tumor vasculature is therefore not aconsequence of, or a trigger for, cell death and destruction, but occurson morphologically intact vascular endothelial cells. This means thatanionic phospholipid expression on tumor vasculature is not transient,but rather is stable enough to provide a target for therapeuticintervention.

Given the finding that anionic phospholipids are stably induced in tumorvasculature, the invention further provides a range of new methods andcompositions for tumor vasculature imaging and destruction usingimmunoconjugates of antibodies against anionic phospholipids. Theseimmunoconjugates comprise antibodies against anionic phospholipids thatare operatively attached to therapeutic agents, such as toxins andcoagulants, and are useful in the specific delivery of diagnostics andtherapeutics to the surface of tumor vascular endothelial cellmembranes. The therapeutic agents are delivered in intimate contact withthe tumor vascular endothelial cell membrane, allowing either rapidentry into the target cell or rapid association with effector cells,components of the coagulation cascade, and such like.

In a second overall embodiment, the invention provides a number ofpreferred antibodies that bind to aminophospholipids and anionicphospholipids (and related immunoconjugates and compositions), whichantibodies have structures and properties that provide advantages overthose known in the art. These so-called “second generation” or improvedantibodies will preferably be used in the anti-angiogenic, anti-cancerand anti-viral and other treatment methods disclosed herein.

The new classes of antibodies that bind to aminophospholipids andanionic phospholipids provided by the present invention overcome variousdrawbacks in the prior art by providing therapeutic antibodies withoutthe pathogenic properties usually associated with antibodies toaminophospholipids and anionic phospholipids in the art. The inventionwas developed, in part, using new immunization and screening techniquesdeveloped from the inventors' unique observations on phospholipidbehaviour in tumor vascular endothelial cells, and distancing theantibodies generated from anti-phospholipid antibodies associated withdisease. Such antibodies not only have unique properties and improvedsafety, but are equally or more effective than existing antibodies incomparative studies. The compositions and methods of these aspects ofinvention also extend to the use of immunoconjugates and combinations,using the specific category of antibodies provided.

Prior to the present invention, antibodies that bind toaminophospholipids and anionic phospholipids and have the properties ofthe new antibodies disclosed herein were not known. However, in light ofthe invention disclosed herein, the art is now provided with themethodology for generating new candidate antibodies and with thetechniques to test such antibodies to identify further useful antibodiesfrom the pool of candidates. In light of this invention, therefore, arange of antibodies with advantageous properties and aminophospholipidand anionic phospholipid binding profiles can be made that do not sufferfrom the notable drawbacks and side effects associated with the priorart antibodies. Such antibodies can thus be used in a variety ofembodiments, including in the inhibition of angiogenesis and thetreatment of cancer and viral infections.

In addition to the new immunization and screening techniques providedherein, antibodies that bind to aminophospholipids and anionicphospholipids and have a number of advantageous properties can now beidentified by competition and/or functional assays using the monoclonalantibodies 1B9, 1B12, 3B10, 2G7, 7C5, 9D2 or 3G4. Currently, the 1B12,3B10, 9D2 and 3G4 antibodies are preferred. Certain of these antibodiesdo not require serum for phospholipid binding. The monoclonal antibodies9D2 and 3G4 are more preferred, with monoclonal antibody 3G4 (ATCC 4545)currently being the most preferred. To identify additional antibodiesthat compete with any of the foregoing antibodies, preferably 3G4, thepreferred assays are currently competition assays based upon an ELISA, anumber of which are described herein, and working examples of which aredisclosed.

In a third overall embodiment, the present invention provides a newclass of cell-impermeant peptide-based derivatives that bind to theaminophospholipid, phosphatidylethanolamine (PE). These “PE-bindingpeptide derivatives” comprise at least a first PE-binding peptide,preferably duramycin, which has been modified to substantially preventnon-specific toxicity, preferably by modifying the PE-binding peptide,preferably duramycin, to form a substantially cell impermeant orsubstantially non-pore forming PE-binding construct.

The generation of a “substantially cell impermeant” or “substantiallynon-pore forming” PE-binding construct or duramycin is preferablyachieved by attaching the PE-binding peptide or duramycin to at least afirst cell impermeant group, preferably a group that prevents clusteringof the PE-binding peptide or duramycin. The synthesis of a number ofexemplary duramycin derivatives is described herein. The “cellimpermeant group or groups” may be small molecules, inert carriers, ormay themselves be targeting agents that impart a further targetingfunction to the resultant construct, such as targeting to tumorvasculature. Thus, the PE-binding peptide can be the sole targetingagent linked to an inert carrier, or can be one of two agents that eachimpart a targeting function to the construct. Additionally, PE-bindingpeptides, preferably duramycin, are operatively attached to effectors,such that the PE-binding peptide or duramycin provides the targetingfunction and the attached agent has a substantial therapeutic effectonce delivered to the target cell. Preferred examples are PE-bindingpeptides or duramycin linked to anti-viral agents, such as nucleosides.

As PE is essentially absent from the surface of normal cells undernormal conditions, the substantially cell impermeant PE-binding peptidesof the present invention function to selectively bind to PE at thesurface of aberrant cells or cells associated with disease, such astumor vascular endothelial cells, proliferating and/or virally infectedcells. Upon binding to such aberrant target cells, the PE-bindingconstructs or derivatives inhibit or interrupt PE functions in thosecells, thus resulting in an overall therapeutic benefit, e.g., in thetreatment of tumors and/or viral diseases. The successful use ofsubstantially cell impermeant PE-binding peptides in inhibiting viralentry and spread is disclosed herein. In embodiments where thePE-binding peptides are attached to anti-viral agents, such ascidofovir, enhanced and safer anti-viral treatment is provided.

In a fourth overall embodiment, the invention further provides animportant new class of compositions and methods for inhibiting viralreplication, infection and spread for use in treating viral infectionsand diseases. These methods are based on the surprising insight thatantibodies and peptides that bind to aminophospholipids and anionicphospholipids, such as PS, PE, PI, PA and PG, particularly PS and PE,would be safe and effective anti-viral agents. Not only has this insightproven to be correct, but the present invention provides data showingthe unexpectedly effective use of antibodies and peptides that bind toaminophospholipids and anionic phospholipids in combating viral spread,meaning that these agents are broadly applicable in the treatment of arange of viral infections and associated diseases.

These discoveries further encompass new categories of immunoconjugates,compositions, kits and methods of use in which an antibody to anaminophospholipid or anionic phospholipid, particularly PS and PE, isoperatively attached to an anti-viral agent. The substantially cellimpermeant PE-binding peptide derivatives, such as the duramycin peptidederivatives, may also be linked to anti-viral agents. Each of theseagents thus provide new anti-viral drugs uniquely targeted to virallyinfected cells.

The development of new safe, therapeutic agents effective in thetreatment of aberrant angiogenesis, cancer and viral infections anddiseases is thus a breakthrough in the art.

Although uniquely effective, the various methods and compositions of thepresent invention can also be used to advantage in combination withother therapies and agents to provide combined treatment methods, andrelated compositions, pharmaceuticals and kits of the invention. In afifth overall embodiment, therefore, the invention further providesparticular combined compositions, methods and kits, e.g. for cancertreatment, which have been selected and discovered to work surprisinglywell together, as explained in more detail herein.

Second Generation Antibodies: Certain methods discovered to functionwell in the generation of antibodies with the sought properties aredescribed herein in Example IV and embodied in the pending claims. Thesemethods permitted the generation of the advantageous antibodies of theinvention as exemplified by the monoclonal antibodies 1B9, 1B12, 3B10,2G7, 7C5, 9D2 and 3G4, particularly 3G4 (ATCC 4545).

The present invention thus provides purified antibodies, antigen-bindingfragments and immunoconjugates thereof, which bind to at least oneaminophospholipid or anionic phospholipid, preferably PS, and thateffectively compete with the monoclonal antibody 1B9, 1B12, 3B10, 2G7,7C5, 9D2 or 3G4, preferably with 9D2 or 3G4 (ATCC 4545), and mostpreferably with 3G4, for binding to the aminophospholipid or anionicphospholipid, preferably PS.

As used throughout the entire application, the terms “a” and “an” areused in the sense that they mean “at least one”, “at least a first”,“one or more” or “a plurality” of the referenced components or steps,except in instances wherein an upper limit is thereafter specificallystated. Therefore, an “antibody”, as used herein, means “at least afirst antibody”. The operable limits and parameters of combinations, aswith the amounts of any single agent, will be known to those of ordinaryskill in the art in light of the present disclosure.

In certain aspects, the antibodies will effectively compete with themonoclonal antibody 1B9, 1B12, 3B10, 2G7, 7C5, 9D2 or 3G4, preferablywith 9D2 or 3G4, and most preferably with 3G4 (ATCC 4545), for bindingto an aminophospholipid or anionic phospholipid, preferably PS, or willhave the aminophospholipid or anionic phospholipid binding profile ofthe monoclonal antibody 1B9, 1B12, 3B10, 2G7, 7C5, 9D2 or 3G4,preferably of 9D2 or 3G4, and most preferably of 3G4, as set forth inTable 4. Certain antibodies will not be serum dependent, i.e., will notrequire serum to bind to the aminophospholipid or anionic phospholipid;not be derived from a patient with a disease, and will not significantlyinhibit coagulation reactions in vitro, cause significant thrombosis invivo or have lupus anticoagulant activities.

Preferably, such antibodies will also demonstrate an improvement instructural properties or in the range or degree of advantageousfunctional properties in controlled studies in comparison to an antibodyin the literature, such as being IgG, having a higher affinity ordemonstrating enhanced binding to activated endothelial cells, increasedinhibition of endothelial cell proliferation or angiogenesis, improvedtumor blood vessel localization, anti-cancer and/or anti-viral effects.

Particular aspects of the invention are therefore based on theinventors' original, surprising generation of antibodies having theforegoing, other disclosed and inherent advantageous properties. Nowthat a panel of preferred antibodies, and a number of particularlypreferred antibodies, have been provided, the present invention furtherencompasses a class of antibodies of defined epitope-specificity,wherein such antibodies, or antigen-binding fragments thereof,effectively compete with the monoclonal antibody 1B9, 1B12, 3B10, 2G7,7C5, 9D2 or 3G4, preferably with 9D2 or 3G4, and most preferably with3G4 (ATCC 4545), for antigen binding, such that they bind to essentiallythe same epitope as the monoclonal antibody 1B9, 1B12, 3B10, 2G7, 7C5,9D2 or 3G4, preferably with 9D2 or 3G4, and most preferably with 3G4(ATCC 4545).

The invention as claimed is enabled in accordance with the presentspecification and readily available technological references, know-howand starting materials. Nonetheless, on behalf of the present Applicant,Board of Regents, The University of Texas System, samples of thehybridoma cell line producing the 3G4 monoclonal antibody were submittedfor deposit with the American Type Culture Collection (ATCC), 10801University Blvd., Manassas, Va. 20110-2209, U.S.A. The samples weresubmitted by Avid Bioservices, Inc., 14272 Franklin Avenue, Tustin,Calif. 92780, U.S.A., a subsidiary of the licensee, PeregrinePharmaceuticals, Inc., during the week beginning Jul. 8, 2002, werereceived on Jul. 10 and Jul. 12, 2002, shown to be viable, and givenATCC Accession number PTA 4545 on Jul. 30, 2002.

This deposit was made under the provisions of the Budapest Treaty on theInternational Recognition of the Deposit of Microorganisms for thePurposes of Patent Procedure and the regulations thereof (BudapestTreaty). The hybridoma will be made available by the ATCC under theterms of the Budapest Treaty upon issue of a U.S. patent with pertinentclaims. Availability of the deposited hybridoma is not to be construedas a license to practice the invention in contravention of the rightsgranted under the authority of any government in accordance with itspatent laws.

In light of the panel of antibodies, the preferred antibodies and thetechniques disclosed herein and known in the art, those of ordinaryskill in the art are now provided with a new class antibodies that bindto aminophospholipids or anionic phospholipids and have advantageousproperties. These antibodies are “like” or “based on” the monoclonalantibodies 1B9, 1B12, 3B10, 2G7, 7C5, 9D2 or 3G4. Preferably, theantibodies of the invention are “9D2-based or 9D2-like antibodies”, andmost preferably, the antibodies of the invention are “3G4-based or3G4-like antibodies”. The following description of “like” antibodies isprovided in terms of the 3G4 antibody (ATCC 4545) for simplicity, but isspecifically incorporated herein by reference as applicable to each ofthe 1B9, 1B 12, 3B10, 2G7, 7C5 and 9D2 antibodies.

A 3G4-like antibody is an antibody, or antigen-binding fragment thereof,that binds to substantially the same epitope as the monoclonal antibody3G4 (ATCC 4545) or that binds to at least a first aminophospholipid oranionic phospholipid, preferably PS, at essentially the same epitope asthe monoclonal antibody 3G4 (ATCC 4545). Preferably, the antibody, orantigen-binding fragment thereof, will bind to the same epitope as themonoclonal antibody 3G4 (ATCC 4545).

The terms “that bind to about, substantially or essentially the same, orthe same, epitope as” the monoclonal antibody 3G4 (ATCC 4545) mean thatan antibody “cross-reacts” with the monoclonal antibody 3G4 (ATCC 4545).“Cross-reactive antibodies” are those that recognize, bind to or haveimmunospecificity for substantially or essentially the same, or thesame, epitope, epitopic site or common aminophospholipid or anionicphospholipid epitope as the monoclonal antibody 3G4 (ATCC 4545) suchthat are able to effectively compete with the monoclonal antibody 3G4(ATCC 4545) for binding to at least one aminophospholipid or anionicphospholipid, more than one aminophospholipid or anionic phospholipid orto all aminophospholipid or anionic phospholipids to which themonoclonal antibody 3G4 (ATCC 4545) binds. “3G4-cross-reactiveantibodies” are succinctly termed “3G4-like antibodies” and “3G4-basedantibodies”, and such terms are used interchangeably herein and apply tocompositions, uses and methods.

The identification of one or more antibodies that bind(s) to about,substantially, essentially or at the same epitope as the monoclonalantibody 3G4 (ATCC 4545) is a straightforward technical matter now that3G4, with its advantageous properties, has been provided. As theidentification of cross-reactive antibodies is determined in comparisonto a reference antibody, it will be understood that actually determiningthe epitope to which the reference antibody (3G4) and the test antibodybind is not in any way required in order to identify an antibody thatbinds to the same or substantially the same epitope as the monoclonalantibody 3G4. However, considerable information on the epitope bound by3G4 is included herein and epitope mapping can be further performed.

The identification of cross-reactive antibodies can be readilydetermined using any one of variety of immunological screening assays inwhich antibody competition can be assessed. All such assays are routinein the art and are further described herein in detail. Each of U.S. Pat.Nos. 6,342,219, 6,342,221, 6,524,583, and 6,416,758 are specificallyincorporated herein by reference for purposes including even furthersupplementing the present teaching concerning how to make antibodiesthat bind to the same or substantially or essentially the same epitopeas a given antibody, such as 3G4, or that effectively compete with agiven antibody for binding to an antigen.

For example, where the test antibodies to be examined are obtained fromdifferent source animals, or are even of a different isotype, a simplecompetition assay may be employed in which the control (3G4) and testantibodies are admixed (or pre-adsorbed) and applied to anaminophospholipid or anionic phospholipid antigen composition,preferably PS. By “aminophospholipid or anionic phospholipid antigencomposition” is meant any composition that contains a 3G4-bindingantigen as described herein, such as described in Table 4. Thus,protocols based upon ELISAs and Western blotting are suitable for use insuch simple competition studies.

In certain embodiments, one would or pre-mix the control antibodies(3G4) with varying amounts of the test antibodies (e.g., 1:10 or 1:100)for a period of time prior to applying to an antigen composition. Inother embodiments, the control and varying amounts of test antibodiescan simply be admixed during exposure to the antigen composition. In anyevent, by using species or isotype secondary antibodies one will be ableto detect only the bound control antibodies, the binding of which willbe reduced by the presence of a test antibody that recognizessubstantially the same epitope.

In conducting an antibody competition study between a control antibodyand any test antibody (irrespective of species or isotype), one mayfirst label the control (3G4) with a detectable label, such as, e.g.,biotin or an enzymatic (or even radioactive) label to enable subsequentidentification. In these cases, one would pre-mix or incubate thelabeled control antibodies with the test antibodies to be examined atvarious ratios (e.g., 1:10, 1:100 or 1:1000) and (optionally after asuitable period of time) then assay the reactivity of the labeledcontrol antibodies and compare this with a control value in which nopotentially competing test antibody was included in the incubation.

The assay may again be any one of a range of immunological assays basedupon antibody hybridization, and the control antibodies would bedetected by means of detecting their label, e.g., using streptavidin inthe case of biotinylated antibodies or by using a chromogenic substratein connection with an enzymatic label (such as3,3′5,5′-tetramethylbenzidine (TMB) substrate with peroxidase enzyme) orby simply detecting a radioactive label. An antibody that binds to thesame epitope as the control antibodies will be able to effectivelycompete for binding and thus will significantly reduce control antibodybinding, as evidenced by a reduction in bound label.

The reactivity of the (labeled) control antibodies in the absence of acompletely irrelevant antibody would be the control high value. Thecontrol low value would be obtained by incubating the labeled (3G4)antibodies with unlabelled antibodies of exactly the same type (3G4),when competition would occur and reduce binding of the labeledantibodies. In a test assay, a significant reduction in labeled antibodyreactivity in the presence of a test antibody is indicative of a testantibody that recognizes the same epitope, i.e., one that “cross-reacts”with the labeled (3G4) antibody.

A significant reduction is a “reproducible”, i.e., consistentlyobserved, reduction in binding. A “significant reduction” in terms ofthe present application is defined as a reproducible reduction (in 3G4binding to one or more aminophospholipid or anionic phospholipids,preferably PS, in an ELISA) of at least about 70%, about 75% or about80% at any ratio between about 1:10 and about 1:1000. Antibodies witheven more stringent cross-blocking activities will exhibit areproducible reduction (in 3G4 binding to one or more aminophospholipidor anionic phospholipids, preferably PS, in an ELISA or other suitableassay) of at least about 82%, about 85%, about 88%, about 90%, about 92%or about 95% or so at any ratio between about 1:10 and about 1:1000.Complete or near-complete cross-blocking, such as exhibiting areproducible reduction in 3G4 binding to one or more aminophospholipidor anionic phospholipids of about 97% or about 96% or so, although by nomeans required to practice the invention, is certainly not excluded.

As to the second generation antibodies overall, the competition may bemeasured in reference to an antibody that at least binds tophosphatidylserine, wherein the second generation antibody effectivelycompetes for binding to phosphatidylserine; in reference to an antibodythat at least binds to phosphatidic acid, wherein the second generationantibody effectively competes for binding to phosphatidic acid; inreference to an antibody that at least binds to phosphatidylinositol,wherein the second generation antibody effectively competes for bindingto phosphatidylinositol; in reference to an antibody that at least bindsto phosphatidylglycerol, wherein the second generation antibodyeffectively competes for binding to phosphatidylglycerol; in referenceto an antibody that at least binds to cardiolipin, wherein the secondgeneration antibody effectively competes for binding to cardiolipin; andoptionally in reference to an antibody that at least binds tophosphatidylethanolamine, wherein the second generation antibodyeffectively competes for binding to phosphatidylethanolamine.

In certain embodiments, the second generation antibodies may be measuredin reference to an antibody that binds to at least a first and secondaminophospholipid or anionic phospholipid, and wherein the secondgeneration antibody effectively competes for binding to the first andsecond aminophospholipid or anionic phospholipid; in reference to anantibody that binds to at least a first, second and thirdaminophospholipid or anionic phospholipid, and wherein the secondgeneration antibody effectively competes for binding to the first,second and third aminophospholipid or anionic phospholipid; in referenceto an antibody that binds to at least a first, second, third and fourthaminophospholipid or anionic phospholipid, and wherein the secondgeneration antibody effectively competes for binding to the first,second, third and fourth aminophospholipid or anionic phospholipid; orin reference to an antibody that binds to at least a first, second,third, fourth and fifth aminophospholipid or anionic phospholipid, andwherein the second generation antibody effectively competes for bindingto the first, second, third, fourth and fifth aminophospholipid oranionic phospholipid.

In further embodiments, a second generation antibody may characterizedas an antibody that exhibits significant binding to at least oneaminophospholipid or anionic phospholipid, no detectable binding to acholine-containing neutral phospholipid and that effectively competeswith a monoclonal antibody of the invention, preferably 3G4 (ATCC 4545).

In particular embodiments, the antibody exhibits significant binding tothe anionic phospholipids PS, PA, PI, PG and CL; has a phospholipidbinding profile of PS=PA=PI=PG>CL>>PE, wherein > indicates at least2-fold difference in binding and >> indicates at least 10-folddifference in binding to such phospholipids; exhibits no detectablebinding to phosphatidylcholine or sphingomyelin; and effectivelycompetes with the monoclonal antibody 3G4 (ATCC 4545) for binding toeach of the anionic phospholipids PS, PA, PI PG and CL.

Preferably, the second generation antibodies will have the foregoingcharacteristics and also exhibits significant binding to at least oneanionic phospholipid present at the cell surface of activated, dividing,injured, apoptotic or virally infected cells. More preferably, theantibody also significantly inhibits the proliferation of dividingendothelial cells without significantly altering quiescent cells, andmore preferably, has no significant lupus anticoagulant activities.

Functionally, the second generation antibodies will preferablysuppresses angiogenesis, have an anti-tumor effect and an anti-viraleffect, preferably in vivo, and more preferably, will do so withoutcausing significant thrombotic complications in animals or patients.Thus, the preferred antibodies possess the combined properties of ananti-angiogenic, anti-tumor vascular, anti-tumor and anti-viral agent.

The invention is exemplified by monoclonal antibody 3G4, produced byhybridoma ATCC 4545, or an antigen-binding fragment of such a monoclonalantibody. A hybridoma that produces a monoclonal antibody that binds tosubstantially the same epitope as the monoclonal antibody 3G4 (ATCC4545) is another aspect of the invention.

The invention further provides antibodies that bind to substantially thesame epitope as the monoclonal antibody 3G4 (ATCC 4545), prepared by aprocess comprising immunizing an animal with a composition comprising atleast a first immunogenic aminophospholipid or anionic phospholipid,including a composition comprising activated endothelial cells, andselecting from the immunized animal an antibody that substantiallycross-reacts with the monoclonal antibody 3G4 (ATCC 4545); andantibodies that bind to substantially the same epitope as the monoclonalantibody 3G4 (ATCC 4545), prepared by a process comprising immunizing ananimal with a composition comprising at least a first immunogenicaminophospholipid or anionic phospholipid, including a compositioncomprising activated endothelial cells, and selecting a competingantibody from the immunized animal by identifying an antibody thatsubstantially reduces the binding of the 3G4 (ATCC 4545) antibody to atleast a first aminophospholipid or anionic phospholipid, preferably PS.

In the following descriptions of the compositions, immunoconjugates,pharmaceuticals, combinations, cocktails, kits, first and second medicaluses and all methods in accordance with this invention, the terms“antibody” and “immunoconjugate”, or an antigen-binding region thereof,unless otherwise specifically stated or made clear from the scientificterminology, refer to a range of anti-aminophospholipid or anti-anionicphospholipid antibodies as well as to specific 3G4-cross-reactiveantibodies.

The terms “antibody” and “immunoglobulin”, as used herein, refer broadlyto any immunological binding agent, including polyclonal and monoclonalantibodies. Depending on the type of constant domain in the heavychains, antibodies are assigned to one of five major classes: IgA, IgD,IgE, IgG, and IgM. Several of these are further divided into subclassesor isotypes, such as IgG1, IgG2, IgG3, IgG4, and the like. Theheavy-chain constant domains that correspond to the difference classesof immunoglobulins are termed α, δ, ε, γ and μ, respectively. Thesubunit structures and three-dimensional configurations of differentclasses of immunoglobulins are well known.

Generally, where antibodies rather than antigen binding regions are usedin the invention, IgG and/or IgM are preferred because they are the mostcommon antibodies in the physiological situation and because they aremost easily made in a laboratory setting. The “light chains” ofmammalian antibodies are assigned to one of two clearly distinct types:kappa (κ) and lambda (λ), based on the amino acid sequences of theirconstant domains. There is essentially no preference to the use of κ orλ light chains in the antibodies of the present invention.

The use of monoclonal antibodies (MAbs) or derivatives thereof is muchpreferred. MAbs are recognized to have certain advantages, e.g.,reproducibility and large-scale production, which makes them suitablefor clinical treatment. The invention thus provides monoclonalantibodies of the murine, human, monkey, rat, hamster, rabbit and evenfrog or chicken origin. Murine, human or humanized monoclonal antibodieswill generally be preferred.

As will be understood by those in the art, the immunological bindingreagents encompassed by the term “antibody” extend to all antibodiesfrom all species, and antigen binding fragments thereof, includingdimeric, trimeric and multimeric antibodies; bispecific antibodies;chimeric antibodies; human and humanized antibodies; recombinant,engineered and camelized (camelised) antibodies, and fragments thereof.

The term “antibody” is thus used to refer to any antibody-like moleculethat has an antigen binding region, and this term includes antibodyfragments such as Fab′, Fab, F(ab′)₂, single domain antibodies (DABs),Fv, scFv (single chain Fv), linear antibodies, diabodies, camelizedantibodies and the like. The techniques for preparing and using variousantibody-based constructs and fragments are well known in the art (seeKabat et al., 1991, specifically incorporated herein by reference).Diabodies, in particular, are further described in EP 404,097 and WO93/11161, each specifically incorporated herein by reference; whereaslinear antibodies are further described in Zapata et al. (1995),specifically incorporated herein by reference.

The antibodies of the invention include those that bind tophosphatidylserine and comprises at least one CDR of an antibodyprovided herein, preferably the 9D2 or 3G4 (ATCC 4545) antibody. Forexample, the invention provides antibodies that bind tophosphatidylserine and comprise at least one CDR from the monoclonalantibody 3G4 produced by the hybridoma deposited as ATCC PTA 4545; or atleast one CDR that has a CDR amino acid sequence encompassed by thevariable region amino acid sequence of SEQ ID NO:2 or SEQ ID NO:4, or avariant or mutagenized form of the amino acid sequence of SEQ ID NO:2 orSEQ ID NO:4, wherein such a variant or mutagenized form maintainsbinding to phosphatidylserine. The heavy chain CDR amino acid sequencesencompassed by the variable region amino acid sequence of SEQ ID NO:2are: VH CDR1 of SEQ ID NO: 10, VH CDR2 of SEQ ID NO: 11 and VH CDR3 ofSEQ ID NO: 12. The light chain CDR amino acid sequences encompassed bythe variable region amino acid sequence of SEQ ID NO:4 are: VL CDR1 ofSEQ ID NO:13, VL CDR2 of SEQ ID NO:14 and VL CDR3 of SEQ ID NO:15.

Certain antibodies thus comprise at least one CDR from the variableregions of each of the heavy and light chains of monoclonal antibody 3G4(ATCC 4545), at least one CDR1-3 of the monoclonal antibody 3G4 (ATCC4545), or CDR1-3 of the variable regions of each of the heavy and lightchains of monoclonal antibody 3G4 (ATCC PTA 4545). Other antibodiescomprise at least a first variable region that includes an amino acidsequence region having the amino acid sequence of SEQ ID NO:2 or SEQ IDNO:4, as exemplified by variable regions that include an amino acidsequence region encoded by the nucleic acid sequences of SEQ ID NO: 1 orSEQ ID NO:3. Such sequences are the sequences of Vh and Vκ of the 3G4ScFv encompassing CDR1-3 (complementarity determining regions) of thevariable regions of the heavy and light chains.

In certain embodiments, second generation antibodies are provided thathave enhanced or superior properties in comparison to an originalanti-aminophospholipid or anti-anionic phospholipid antibody, such as3G4 (ATCC 4545). These are exemplified by antibodies that comprise atleast one CDR that has a variant or mutagenized form of the amino acidsequence of SEQ ID NO:2 or SEQ ID NO:4, wherein such a variant ormutagenized form maintains binding to phosphatidylserine.

The anti-aminophospholipid or anti-anionic phospholipid antibodies thusinclude those that comprises at least a first variable region thatincludes an amino acid sequence region of at least about 75%, morepreferably, at least about 80%, more preferably, at least about 85%,more preferably, at least about 90% and most preferably, at least about95% or so amino acid sequence identity to the amino acid sequence of SEQID NO:2 or SEQ ID NO:4; wherein said anti-aminophospholipid oranti-anionic phospholipid antibody at least substantially maintains thebiological properties of the anti-aminophospholipid or anti-anionicphospholipid antibodies of the present invention, as exemplified by the3G4 antibody.

Identity or homology with respect to these and otheranti-aminophospholipid or anti-anionic phospholipid antibody sequencesof the present invention is defined herein as the percentage of aminoacid residues in a candidate sequence that are identical to thesequences of SEQ ID NO:2 or SEQ ID NO:4, or to the sequence of anotheranti-aminophospholipid or anti-anionic phospholipid antibody of theinvention, after aligning the sequences and introducing gaps, ifnecessary, to achieve the maximum percent sequence identity. Themaintenance of substantially the same, or even more effective biologicalproperties of the anti-aminophospholipid or anti-anionic phospholipidantibody used for the sequence comparison is particularly important.Such comparisons are easily conducted, e.g., using one or more of thevarious assays described in detail herein.

In further embodiments, the antibodies employed will be “humanized”,part-human or human antibodies. “Humanized” antibodies are generallychimeric monoclonal antibodies from mouse, rat, or other non-humanspecies, bearing human constant and/or variable region domains(“part-human chimeric antibodies”). Various humanized monoclonalantibodies for use in the present invention will be chimeric antibodieswherein at least a first antigen binding region, or complementaritydetermining region (CDR), of a mouse, rat or other non-human monoclonalantibody is operatively attached to, or “grafted” onto, a human antibodyconstant region or “framework”.

“Humanized” monoclonal antibodies for use herein may also be monoclonalantibodies from non-human species wherein one or more selected aminoacids have been exchanged for amino acids more commonly observed inhuman antibodies. This can be readily achieved through the use ofroutine recombinant technology, particularly site-specific mutagenesis.

Entirely human, rather than “humanized”, antibodies may also be preparedand used in the present invention. Such human antibodies may be obtainedfrom healthy subjects by simply obtaining a population of mixedperipheral blood lymphocytes from a human subject, includingantigen-presenting and antibody-producing cells, and stimulating thecell population in vitro by admixing with an immunogenically effectiveamount of an aminophospholipid or anionic phospholipid sample. The humananti-aminophospholipid or anti-anionic phospholipid antibody-producingcells, once obtained, are used in hybridoma and/or recombinant antibodyproduction.

Further techniques for human monoclonal antibody production includeimmunizing a transgenic animal, preferably a transgenic mouse, whichcomprises a human antibody library with an immunogenically effectiveamount of an aminophospholipid or anionic phospholipid sample. This alsogenerates human anti-aminophospholipid or anti-anionic phospholipidantibody-producing cells for further manipulation in hybridoma and/orrecombinant antibody production, with the advantage that spleen cells,rather than peripheral blood cells, can be readily obtained from thetransgenic animal or mouse.

Antibodies in accordance with the invention may be readily prepared byselecting an antibody that substantially cross-reacts or competes withthe monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545). Suitable preparativeprocesses and methods comprise:

-   -   (a) preparing candidate antibody-producing cells; and    -   (b) selecting from the candidate antibody-producing cells an        antibody that substantially cross-reacts or competes with the        monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545).

One process of preparing suitable antibody-producing cells and obtainingantibodies therefrom may be conduced in situ in a given patient. Thatis, simply providing an immunogenically effective amount of animmunogenic aminophospholipid or anionic phospholipid sample to apatient will result in appropriate antibody generation. Thus, theantibody is still “obtained” from the antibody-producing cell, but itdoes not have to be isolated away from a host and subsequently providedto a patient, being able to spontaneously localize to the tumorvasculature and exert its biological anti-tumor effects. However, suchembodiments are not currently preferred.

Suitable antibody-producing cells may also be obtained, and antibodiessubsequently isolated and/or purified, by stimulating peripheral bloodlymphocytes with aminophospholipid or anionic phospholipid in vitro.

Other methods comprise administering to an animal an immunizingcomposition comprising at least a first immunogenic aminophospholipid oranionic phospholipid component and selecting from the immunized animalan antibody that substantially cross-reacts or competes with themonoclonal antibody 9D2 or 3G4 (ATCC PTA 4545). These methods generallycomprise:

-   -   (a) immunizing an animal by administering to the animal at least        one dose, and optionally more than one dose, of a composition        comprising an immunogenically effective amount of an immunogenic        aminophospholipid or anionic phospholipid; and    -   (b) obtaining a suitable antibody-producing cell from the        immunized animal, such as an antibody-producing cell that        produces an antibody that substantially cross-reacts or competes        with the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545).

A preferred “composition comprising an immunogenically effective amountof an immunogenic aminophospholipid or anionic phospholipid”, as usedherein, is a composition comprising activated endothelial cells.“Activated endothelial cells” are preferably prepared by placingendothelial cells under at least a first condition, or in contact withat least a first factor, which activates the endothelial cells, and/ormimics a tumor environment, for a time effective to substantiallymaintain cell viability and stimulate expression of at least one anionicphospholipid at the surface of the endothelial cells.

Examples “conditions” effective to prepare activated endothelial cellsare hypoxic and/or acidic environments. Examples of “factors” effectiveto prepare activated endothelial cells are effective concentrations ofH₂O₂, thrombin, inflammatory cytokine(s), such as IL-1α, IL-1β,interferon or TNFα, and generally, combinations of conditions and/orfactors that mimic a tumor environment.

Irrespective of the nature of the immunization process, or the type ofimmunized animal, suitable antibody-producing cells are obtained fromthe immunized animal and, preferably, further manipulated by the hand ofman. “An immunized animal”, as used herein, is a non-human animal,unless otherwise expressly stated. Although any antibody-producing cellmay be used, most preferably, spleen cells are obtained as the source ofthe antibody-producing cells. The antibody-producing cells may be usedin a preparative process that comprises:

-   -   (a) fusing a suitable anti-aminophospholipid or anti-anionic        phospholipid antibody-producing cell with an immortal cell to        prepare a hybridoma that produces a monoclonal antibody in        accordance with the present invention; and    -   (b) obtaining a suitable anti-aminophospholipid or anti-anionic        phospholipid antibody in accordance with the invention from the        hybridoma.

“Suitable” anti-aminophospholipid or anti-anionic phospholipidantibody-producing cells, hybridomas and antibodies are those thatproduce, or exist as, anti-aminophospholipid or anti-anionicphospholipid antibodies, preferably antibodies that substantiallycross-react or compete with the monoclonal antibody 9D2 or 3G4 (ATCC PTA4545).

Hybridoma-based monoclonal antibody preparative methods thus includethose that comprise:

-   -   (a) immunizing an animal by administering to the animal at least        one dose, and optionally more than one dose, of a composition        comprising an immunogenically effective amount of an immunogenic        aminophospholipid or anionic phospholipid, preferably a        composition comprising activated endothelial cells;    -   (b) preparing a collection of monoclonal antibody-producing        hybridomas from the immunized animal;    -   (c) selecting from the collection at least a first hybridoma        that produces at least a first anti-aminophospholipid or        anti-anionic phospholipid monoclonal antibody in accordance with        the invention, optionally an anti-aminophospholipid or        anti-anionic phospholipid antibody that substantially        cross-reacts or competes with the monoclonal antibody 9D2 or 3G4        (ATCC PTA 4545); and    -   (d) culturing the at least a first antibody-producing hybridoma        to provide the at least a first anti-aminophospholipid or        anti-anionic phospholipid monoclonal antibody; and preferably    -   (e) obtaining the at least a first anti-aminophospholipid or        anti-anionic phospholipid monoclonal antibody from the cultured        at least a first hybridoma.

In identifying an anti-aminophospholipid or anti-anionic phospholipidantibody that substantially cross-reacts with the monoclonal antibody9D2 or 3G4 (ATCC PTA 4545), the selecting step may comprise:

-   -   (a) contacting an aminophospholipid or anionic phospholipid        sample, preferably a PS sample, with effective amounts of the        monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545) and a candidate        antibody; and    -   (b) determining the ability of the candidate antibody to        substantially reduce the binding of the 9D2 or 3G4 antibody to        the aminophospholipid or anionic phospholipid, preferably PS,        sample; wherein the ability of a candidate antibody to        substantially reduce the binding of the 9D2 or 3G4 antibody to        the aminophospholipid or anionic phospholipid, preferably PS        sample is indicative of an anti-aminophospholipid or        anti-anionic phospholipid antibody that binds to substantially        the same epitope as the monoclonal antibody 9D2 or 3G4 (ATCC PTA        4545).

The selecting step may further comprise:

-   -   (a) contacting a first aminophospholipid or anionic phospholipid        sample, preferably PS, with an effective binding amount of the        monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545) and determining        the amount of 9D2 or 3G4 that binds to he aminophospholipid or        anionic phospholipid, preferably PS;    -   (b) contacting a second aminophospholipid or anionic        phospholipid sample, preferably PS, with an effective binding        amount of the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545) in        combination with an effective competing amount of a candidate        antibody and determining the amount of 9D2 or 3G4 that binds to        the aminophospholipid or anionic phospholipid, preferably PS, in        the presence of the candidate antibody; and    -   (c) identifying an anti-aminophospholipid or anti-anionic        phospholipid antibody that binds to substantially the same        epitope as the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545) by        selecting a candidate antibody that reduces the amount of 9D2 or        3G4 that binds to the aminophospholipid or anionic phospholipid,        preferably PS, preferably by at least about 80%.

Certain selection criteria, as used herein, are preferably conducted inthe absence of serum, to avoid the drawbacks with generating antibodiesthat could mimic the pathological antibodies of patients, which bind toaminophospholipids or anionic phospholipids in conjunction withproteins.

As non-human animals are used for immunization, the monoclonalantibodies obtained from such a hybridoma will often have a non-humanmake up. Such antibodies may be optionally subjected to a humanizationprocess, grafting or mutation, as known to those of skill in the art andfurther disclosed herein. Alternatively, transgenic animals, such asmice, may be used that comprise a human antibody gene library.Immunization of such animals will therefore directly result in thegeneration of suitable human antibodies.

After the production of a suitable antibody-producing cell, mostpreferably a hybridoma, whether producing human or non-human antibodies,the monoclonal antibody-encoding nucleic acids may be cloned to preparea “recombinant” monoclonal antibody. Any recombinant cloning techniquemay be utilized, including the use of PCR™ to prime the synthesis of theantibody-encoding nucleic acid sequences. Therefore, yet furtherappropriate monoclonal antibody preparative methods include those thatcomprise using the antibody-producing cells as follows:

-   -   (a) obtaining at least a first suitable anti-aminophospholipid        or anti-anionic phospholipid antibody-encoding nucleic acid        molecule or segment from a suitable anti-aminophospholipid or        anti-anionic phospholipid antibody-producing cell, preferably a        hybridoma; and    -   (b) expressing the nucleic acid molecule or segment in a        recombinant host cell to obtain a recombinant        anti-aminophospholipid or anti-anionic phospholipid monoclonal        antibody in accordance with the present invention.

However, other powerful recombinant techniques are available that areideally suited to the preparation of recombinant monoclonal antibodies.Such recombinant techniques include the phagemid library-basedmonoclonal antibody preparative methods comprising:

-   -   (a) immunizing an animal by administering to the animal at least        one dose, and optionally more than one dose, of a composition        comprising an immunogenically effective amount of an immunogenic        aminophospholipid or anionic phospholipid, preferably a        composition comprising activated endothelial cells;    -   (b) preparing a combinatorial immunoglobulin phagemid library        expressing RNA isolated from the antibody-producing cells,        preferably from the spleen, of the immunized animal;    -   (c) selecting from the phagemid library at least a first clone        that expresses at least a first anti-aminophospholipid or        anti-anionic phospholipid antibody, optionally one that        substantially cross-reacts or competes with the monoclonal        antibody 9D2 or 3G4 (ATCC PTA 4545);    -   (d) obtaining anti-aminophospholipid or anti-anionic        phospholipid antibody-encoding nucleic acids from the at least a        first selected clone and expressing the nucleic acids in a        recombinant host cell to provide the at least a first        anti-aminophospholipid or anti-anionic phospholipid antibody;        and preferably    -   (e) obtaining the at least a first anti-aminophospholipid or        anti-anionic phospholipid antibody expressed by the nucleic        acids obtained from the at least a first selected clone.

Again, in such phagemid library-based techniques, transgenic animalsbearing human antibody gene libraries may be employed, thus yieldingrecombinant human monoclonal antibodies.

Irrespective of the manner of preparation of a firstanti-aminophospholipid or anti-anionic phospholipid antibody nucleicacid segment, further suitable antibody nucleic acid segments may bereadily prepared by standard molecular biological techniques. In orderto confirm that any variant, mutant or second generationanti-aminophospholipid or anti-anionic phospholipid antibody nucleicacid segment is suitable for use in the present invention, the nucleicacid segment will be tested to confirm expression of ananti-aminophospholipid or anti-anionic phospholipid antibody inaccordance with the present invention. Preferably, the variant, mutantor second generation nucleic acid segment will also be tested to confirmhybridization under standard, more preferably, standard stringenthybridization conditions. Exemplary suitable hybridization conditionsinclude hybridization in about 7% sodium dodecyl sulfate (SDS), about0.5 M NaPO₄, about 1 mM EDTA at about 50° C.; and washing with about 1%SDS at about 42° C.

As a variety of recombinant monoclonal antibodies, whether human ornon-human in origin, may be readily prepared, any of the treatmentmethods of the invention may be executed by providing to the animal orpatient at least a first nucleic acid segment that expresses abiologically effective amount of at least a first anti-aminophospholipidor anti-anionic phospholipid antibody in the patient. The “nucleic acidsegment that expresses an anti-aminophospholipid or anti-anionicphospholipid, 3G4-like or 3G4-based antibody” will generally be in theform of at least an expression construct, and may be in the form of anexpression construct comprised within a virus or within a recombinanthost cell. Preferred gene therapy vectors of the present invention willgenerally be viral vectors, such as comprised within a recombinantretrovirus, herpes simplex virus (HSV), adenovirus, adeno-associatedvirus (AAV), cytomegalovirus (CMV), and the like.

Cell Impermeant Duramycin Derivatives: The invention further providessubstantially cell impermeant phosphatidylethanolamine (PE)-bindingpeptide constructs and derivatives, which comprise at least a firstPE-binding peptide that has been modified to form a substantially cellimpermeant PE-binding construct.

Preferably, the invention provides pharmaceutical compositionscomprising, in a pharmaceutically acceptable carrier, a biologically ortherapeutically effective amount of at least a first substantially cellimpermeant PE-binding construct, which comprises at least a firstPE-binding peptide that has been modified to form a substantially cellimpermeant PE-binding construct. Thus, the substantially cell impermeantPE-binding constructs are constructs for pharmaceutical, pharmacologicaland therapeutic, i.e., medical uses, preferably for use in treatingviral infections. In certain embodiments, the invention provides asubstantially cell impermeant PE-binding construct other than cinnamycinlinked to biotin.

Most preferably, the substantially cell impermeant PE-binding peptidederivatives of the invention are substantially cell impermeant duramycinpeptide derivatives and pharmaceutical compositions thereof. Theduramycin peptide is typically modified to form a substantially cellimpermeant duramycin derivative by operative attachment to at least afirst substantially cell impermeant group. Operative attachment of asubstantially cell impermeant group may be via the lysine residue atamino acid position 2 in SEQ ID NO:9.

The substantially cell impermeant group may have a positive or negativecharge at physiological pH or may be polar at physiological pH.Exemplary groups include sulfate, sulfonate, phosphate, carboxyl,phenolic, quaternary ammonium ion and amine groups. A pharmaceuticalcomposition comprising duramycin linked to biotin is a particularexample within the invention.

Substantially cell impermeant duramycins may also be operativelyattached to a sugar, oligo- or polysaccharide, amino acid, peptide,polypeptide, protein or a polyalcohol group. Certain cell impermeantduramycins are those operatively attached to a carrier protein or “aninert carrier protein”, such as neutravidin, streptavidin, albumin or animmunoglobulin carrier protein (an inert immunoglobulin carrierprotein), of which duramycin attached to human IgG (HIgG) isparticularly preferred. Other examples of cell impermeant duramycins arethose linked to targeting agents, preferably wherein the targeting agentis a protein, antibody, or antigen binding region thereof, that binds toa component of a tumor cell, tumor vasculature or tumor stroma or to avirally-infected cell. Examples of targeting agents that bind to acomponent of a tumor cell, tumor vasculature or tumor stroma are taughtin U.S. Pat. Nos. 6,093,399, 6,004,555, 5,877,289, and 6,036,955, eachspecifically incorporated herein by reference.

Conjugates, Compositions and Kits: Unless otherwise specifically statedor made clear in scientific terms, the terms “antibody and fragmentthereof”, as used herein, therefore mean an “unconjugated or naked”antibody or fragment, which is not attached to another agent,particularly a therapeutic or diagnostic agent. These definitions do notexclude modifications of the antibody, such as, by way of example,modifications to improve the biological half life, affinity, avidity orother properties of the antibody, or combinations of the antibody withother effectors.

Similarly, the terms PE-binding peptide and duramycin “derivative”, asused herein, mean PE-binding and duramycin peptides that are notspecifically attached to a selected therapeutic agent, particularly ananti-viral agent. Naturally, as the preferred PE-binding peptide andduramycin “derivatives” of the invention are already attached to atleast a first substantially cell impermeant group, this definitionrefers to the lack of an attached agent “selected” for a therapeuticeffect, particularly an anti-viral effect.

The invention further provides a range of antibody (immunoconjugate) andpeptide conjugates. The immunoconjugates of the invention comprise ananti-aminophospholipid or anti-anionic phospholipid antibody, preferablyone that binds to substantially the same epitope as, or competes with,the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), operatively attachedto at least a first biological, diagnostic or therapeutic agent. Any ofthe range of antibodies described above may be used in such animmunoconjugate.

The “biological agent” need not directly be a therapeutic or diagnosticagent. For example, as the invention can be used in connection withprodrugs, including ADEPT embodiments, the biological agent may be anagent, preferably an enzyme, which cleaves a substantially inactiveprodrug to release a substantially active drug. Such agents and enzymesare described below in relation to the prodrug and ADEPT methodembodiments.

As to “diagnostic agents”, preferred diagnostic agents for attachmentare in vivo diagnostic agents. Such diagnostic immunoconjugates may beused in imaging pre-apoptotic and apoptotic cells in a range ofdiseases, in combined tumor imaging and treatment, and in methods ofusing the invention as a surrogate marker to monitor chemotherapy.

Suitable detectable labels include an X-ray detectable compound, such asbismuth (III), gold (III), lanthanum (III) or lead (II); a radioactiveion, such as copper⁶⁷, gallium⁶⁷, gallium⁶⁸, indium¹¹¹, indium¹¹³,iodine¹²³, iodine¹²⁵, iodine¹³¹, mercury¹⁹⁷, mercury²⁰³, rhenium¹⁸⁶,rhenium¹⁸⁸, rubidium⁹⁷, rubidium¹⁰³, technetium^(99m) or yttrium⁹⁰; anuclear magnetic spin-resonance isotope, such as cobalt (II), copper(II), chromium (III), dysprosium (III), erbium (III), gadolinium (III),holmium (III), iron (II), iron (III), manganese (II), neodymium (III),nickel (II), samarium (III), terbium (III), vanadium (II) or ytterbium(III); or rhodamine or fluorescein.

Regarding “therapeutic agents”, certain preferred therapeutic agents arecytotoxic, cytostatic or anti-cancer agents. The antibodies of theinvention, preferably 9D2- or 3G4-like antibodies, may therefore belinked to at least a first radiotherapeutic, chemotherapeutic,anti-cellular, cytotoxic, anti-angiogenic or apoptosis-inducing agent orto an anti-tubulin drug or cytokine.

Currently preferred agents are the cytotoxic agent, gelonin; cytokines,such as TNFα, IL-12 and LEC (liver-expressed chemokine); anti-canceragents with anti-angiogenic effects, as in Table E; anti-cancer agentsthat induce apoptosis, as in Table F; and anti-tubulin drugs from thecombretastatin family.

For attachment to at least a first biological, diagnostic, cytotoxic,cytostatic or anti-cancer agent, antibodies that bind to substantiallythe same epitope as, i.e., compete with, the monoclonal antibody 9D2 or3G4 (ATCC PTA 4545) are particularly preferred. Given the surprisingconnection between the antibodies and peptides of the invention andviral infections, the present invention further provides a range of newtherapeutic conjugates for use in treating viral infections. Otherpreferred therapeutic agents for attachment to antibodies are thereforeanti-viral agents or drugs. The anti-viral immunoconjugates of theinvention comprise an antibody that binds to at least a firstaminophospholipid or anionic phospholipid, preferably to anaminophospholipid, and most preferably to PS or PE, operatively attachedto at least a first anti-viral agent or drug.

The peptide conjugates of the invention comprise a substantially cellimpermeant PE-binding peptide, preferably a duramycin peptide,operatively attached to at least a first anti-viral agent or drug. Suchpeptide conjugates are herein termed “PE-binding peptide anti-viralconjugates” or succinctly, “anti-viral peptide conjugates”. Any of therange of PE-binding peptides described above may be used in such aconjugate, with duramycin being particularly preferred.

Virtually any one or more “anti-viral agents or drugs” may be attachedto an antibody that binds to at least a first aminophospholipid oranionic phospholipid, preferably to an aminophospholipid, and mostpreferably to PS or PE; or to a PE-binding peptide, preferably aduramycin peptide. Anti-retroviral drugs may be used, for example,nucleoside reverse transcriptase (RT) inhibitors (NTRIs), non-nucleosideRT inhibitors and protease inhibitors. Other suitable anti-viral agentsfor attachment to the antibodies and peptides of the invention includethose set forth in Table G, particularly AZT or cidofovir.

For antibody- and peptide-based conjugates, the term “conjugate” isgenerally used to define the operative association of the antibody orpeptide with another effective agent and is not intended to refer solelyto any type of operative association, and is particularly not limited tochemical “conjugation”. Recombinant fusion proteins are particularlycontemplated. So long as the antibody or peptide is able to bind to thetarget aminophospholipid or anionic phospholipid and the attached agentfunctions sufficiently as intended, particularly when delivered to thetarget site, any mode of attachment will be suitable.

The invention further provides compositions comprising at least a firstpurified anti-aminophospholipid or anti-anionic phospholipid antibody,or antigen-binding fragment or immunoconjugate thereof, optionally onethat binds to essentially the same epitope as the monoclonal antibody9D2 or 3G4 (ATCC PTA 4545), or a substantially cell impermeantPE-binding peptide derivative, preferably a substantially cellimpermeant duramycin derivative, or an anti-viral conjugate thereof. Thecompositions preferably comprise a biologically effective amount of anysuch agent, such as an amount effective to bind a target antigen,inhibit proliferation, viral replication or such like.

The compositions of the invention are preferably pharmaceuticallyacceptable compositions, particularly those for the substantially cellimpermeant PE-binding peptide derivatives, preferably substantially cellimpermeant duramycin derivatives. The pharmaceutical compositionsinclude those formulated for parenteral administration, such as forintravenous administration, or for administration as a liposome or as anaerosol. The aerosol formulations are particularly suitable for treatingviral infections. Pharmaceutical compositions preferably comprise abiologically or therapeutically effective amount of any such agent, suchas an amount effective for treating a disease or disorder, particularlyangiogenesis, cancer or a viral infection.

Aspects of the invention further include compositions, pharmaceuticalcompositions, combinations, mixtures, medicaments and/or medicinalcocktails of agents, comprising at least a first purifiedanti-aminophospholipid or anti-anionic phospholipid antibody, orantigen-binding fragment or immunoconjugate thereof, optionally one thatbinds to essentially the same epitope as the monoclonal antibody 9D2 or3G4 (ATCC PTA 4545), or a substantially cell impermeant PE-bindingpeptide derivative, preferably a substantially cell impermeant duramycinderivative, or an anti-viral conjugate thereof, in combination with abiologically or therapeutically effective amount of at least a secondbiological agent. All such combinations preferably comprise combinedbiologically or therapeutically effective amounts, such as combinedamounts effective to inhibit proliferation or viral replication, or totreat a disease such as an angiogenic disease, cancer or a viralinfection.

In the compositions, the “at least a second biological agent” will oftenbe a diagnostic or therapeutic agent, but it need not be. For example,the second biological agent may be a component of a pharmaceuticalcomposition such as a dispersion agent or an absorption delaying agent.Other biological agents, such as agents for making antibodies andprodrugs for use in prodrug and ADEPT methods, and diagnostic agents,are preferably maintained in combination, but separately, from the firstcomposition of the invention and are therefore discussed below inreference to the kits of the invention. “In combination, but separately”means in close confinement together, but not part of the samecomposition, such as not part of the same solution or pharmaceuticalcomposition.

As to the “at least a second therapeutic agent”, the term “second” is inreference to the anti-aminophospholipid or anti-anionic phospholipidantibody, fragment or immunoconjugate, or substantially cell impermeantPE-binding peptide, duramycin derivative or anti-viral conjugatethereof, being the “first” therapeutic agent.

Where the invention is intended for use in cancer treatment, the atleast a second therapeutic agent will preferably be “at least a second,distinct anti-cancer agent”. The second, anti-cancer agents for combineduse may be radiotherapeutic, chemotherapeutic, anti-angiogenic orapoptosis-inducing agents, cytokines or antibodies or anantibody-therapeutic agent constructs that bind to a tumor cell, anintracellular antigen released from a necrotic tumor cell or to acomponent of tumor vasculature (i.e., anti-cancer immunotoxins orcoaguligands). The term “chemotherapeutic agent”, as used herein,includes genes, vectors, antisense constructs and ribozymes.

Certain preferred second, anti-cancer agents for combined use are thosethat complement or enhance the therapeutic effect of theanti-aminophospholipid or anti-anionic phospholipid antibody orsubstantially cell impermeant PE-binding peptide derivative and/or thoseselected for a particular tumor type or patient. “Therapeutic agentsthat complement or enhance the therapeutic effect” includeradiotherapeutic agents, vascular permeability enhancing agents,anti-angiogenic agents, apoptosis-inducing agents, certain cytokines,anti-tumor cell immunotoxins, as well as selected chemotherapeuticagents. Currently preferred “selected chemotherapeutic agents” arechemotherapeutic agents with anti-angiogenic effects, as in Table E;chemotherapeutic agents that induce apoptosis, as in Table F; calciumflux inducing agents, inflammatory cytokines, H₂O₂, thrombin, andanti-tubulin drugs from the combretastatin family. Doxorubicin,etoposide and actinomycin-D are further preferred, with docetaxel beingmost preferred.

The invention further provides a liposome, lipid carrier, complex,mixture, supramolecular structure multimolecular aggregate orlipid-based drug delivery system comprising at least a first purifiedanti-aminophospholipid or anti-anionic phospholipid antibody, orantigen-binding fragment or immunoconjugate thereof, preferably one thatbinds to essentially the same epitope as the monoclonal antibody 9D2 or3G4 (ATCC PTA 4545), or a substantially cell impermeant PE-bindingpeptide derivative, preferably a substantially cell impermeant duramycinderivative, or an anti-viral conjugate thereof. The liposome orliposome-like composition may be in the form of a monolayer, bilayer,multimolecular aggregate, vesicle, helix, disc, tube, fiber, torus,hexagonal phase, gel phase, liquid-crystalline phase, liquid-crystallinemultimolecular aggregate, micelle, reverse micelle, microemulsion,emulsion, microreservoir, oil globule, fat globule, wax globule and/orcolloidal particle.

Liposomes or liposome-like compositions generally comprise an “outermembrane” or bulk aqueous phase and “central core” or inner aqueousphase. In preferred embodiments, the liposome or liposome-likecomposition is a stealthed liposome, lipid carrier, complex, mixture,supramolecular structure multimolecular aggregate or lipid-based drugdelivery system. “Stealthed” liposomes and liposome-like compositionscomprise a biologically effective amount of at least a first stealthingagent in operative association with the outer membrane. A “stealthingagent” is a component that increases the biological half life of aliposome or liposome-like composition when operatively associated withthe outer membrane of the liposome or liposome-like composition. In“operative association”, the outer membrane of the liposome orliposome-like composition is preferably “coated” with the one or morestealthing agents.

Effective stealthing agents include a range of biocompatible hydrophilicpolymers, such as polyamines, polylactic acid, polyglycolic acid,polylactic-polyglycolic acid (PLGA), polypeptides and related materials.A preferred stealthing agent is polyethylene glycol (PEG) component,wherein the resulting stealthed liposomes are termed “PEGylatedliposomes”.

Preferred liposomes of the invention are stealthed or PEGylatedliposomes wherein an antibody to an aminophospholipid or anionicphospholipid, or antigen-binding fragment thereof, preferably one thatcompetes with the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), isoperatively associated with the outer membrane of the liposome,preferably where the liposome is “coated” with the antibody or fragmentthereof.

Particularly preferred liposomes are such “antibody-coated” stealthed orPEGylated liposomes wherein at least a first therapeutic agent, such asan anti-viral agent or preferably an anti-cancer agent, is operativelyassociated with the liposome or dispersed within the liposomalformulation. Preferably, the therapeutic, anti-viral or anti-canceragent is operatively associated with or maintained within the centralcore of the liposome. Exemplary anti-cancer agents are radionuclide(s)and chemotherapeutic agents, such as anti-tubulin drugs, docetaxel andpaclitaxel, with docetaxel being preferred.

For combinations with biological, diagnostic, anti-angiogenic,anti-cancer agents and stealthed liposomes, antibodies that bind tosubstantially the same epitope as, i.e., compete with, the monoclonalantibody 9D2 or 3G4 (ATCC PTA 4545) are particularly preferred. Wherethe invention is intended for use in treating a viral infection ordisease, the at least a second therapeutic agent will preferably be “atleast a second, anti-viral agent or drug”. The invention thus alsoprovides a range of combined anti-viral compositions and formulations,not limited to the 3G4 and like antibodies.

These aspects of the invention can be conveniently described as acomposition, pharmaceutical composition, combination, mixture,medicament and/or medicinal cocktail comprising at least a firstanti-viral agent or drug in combination with a biologically ortherapeutically effective amount of at least one purifiedanti-aminophospholipid or anti-anionic phospholipid antibody, orantigen-binding fragment or immunoconjugate thereof, optionally one thatbinds to essentially the same epitope as the monoclonal antibody 9D2 or3G4 (ATCC PTA 4545), or a substantially cell impermeant PE-bindingpeptide derivative, preferably a substantially cell impermeant duramycinderivative, or an anti-viral conjugate thereof.

In the foregoing description, the anti-viral agent or drug is recited asthe “at least a first anti-viral agent or drug” and the antibody,fragment, immunoconjugate, substantially cell impermeant PE-bindingpeptide, duramycin derivative or an anti-viral conjugate thereof isrecited as the second component of the combination. This is a matter ofgrammatical convenience.

The one or more anti-viral agents or drugs for use in the presentcombined compositions may be selected from any anti-viral agent or drugavailable at the time of practicing the invention, including the rangeof anti-viral agents and drugs described herein for attachment toantibodies and peptides of the invention. By way of example,anti-retroviral drugs such as NTRIs, non-nucleoside RT inhibitors andprotease inhibitors, anti-viral agents as set forth in Table G, andpreferably, AZT or cidofovir.

Further embodiments of the invention concern kits comprising, in atleast a first composition or container, at least a first purifiedanti-aminophospholipid or anti-anionic phospholipid antibody, orantigen-binding fragment or immunoconjugate thereof, optionally one thatbinds to essentially the same epitope as the monoclonal antibody 9D2 or3G4 (ATCC PTA 4545), or a substantially cell impermeant PE-bindingpeptide derivative, preferably a substantially cell impermeant duramycinderivative, or an anti-viral conjugate thereof, in combination with abiologically or therapeutically effective amount of at least a secondbiological agent, component or system.

The “second biological agents, components or systems” are not limited totherapeutic or diagnostic agents. For example, second biological agents,components or systems may comprise components for modification of theantibody and/or for attaching other agents to the antibody. Certainpreferred second biological agents, components or systems are prodrugsor components for making and using prodrugs, including components formaking the prodrug itself and components for adapting the antibodies ofthe invention to function in such prodrug or ADEPT embodiments.

The at least a “second diagnostic agent, component or system” may be adiagnostic agent, component or system directly or indirectly detectableby an in vitro diagnostic test. “Directly detectable in vitro reporteragents” include radiolabels, reporter agents detectable byimmunofluorescence and luciferase. “Indirectly detectable in vitroreporter agents” function in conjunction with further exogenousagent(s), such as detectable enzymes that yield a colored product oncontact with a chromogenic substrate. These include “secondaryantibodies”, which are attached to a direct or indirect detectableagent, such a radiolabel or enzyme, and “secondary and tertiary antibodydetection systems” in which the tertiary antibody is attached to thedetectable agent.

Preferred diagnostic kits of the invention are those comprising adiagnostic agent, component or system detectable by in vivo diagnosis orimaging. An advantage of the imaging embodiments of the invention isthat the same antibody can be used for imaging and treatment. Theinvention therefore provides kits and medicaments that comprise:

-   -   (a) a first pharmaceutical composition comprising a        diagnostically effective amount of an anti-aminophospholipid or        anti-anionic phospholipid antibody, or antigen-binding fragment        thereof, preferably one that binds to essentially the same        epitope as the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545),        operatively attached to a detectable label or diagnostic agent;        and    -   (b) a second pharmaceutical composition comprising a        therapeutically effective amount of anti-aminophospholipid or        anti-anionic phospholipid antibody, or antigen-binding fragment        or immunoconjugate thereof, preferably one that binds to        essentially the same epitope as the monoclonal antibody 9D2 or        3G4 (ATCC PTA 4545).

For use in therapeutic embodiments, the kits will comprise “at least asecond therapeutic agent”. Preferably, such kits comprise a combinedbiologically or therapeutically effective amount of at least the twospecified agents, such as combined amounts effective to inhibitproliferation or viral replication, or to treat a disease such as anangiogenic disease, cancer or a viral infection.

In terms of cancer treatment, the kits of the invention includeantibodies for use in combination with prodrugs and ADEPT. In suchcompositions, the antibody or fragment thereof is “modified to provide aconverting or enzymatic capacity”. This can be achieved by making acatalytic antibody. Preferably, the antibody is operatively associatedwith, preferably covalently linked or conjugated to, at least a firstconverting agent or enzyme capable of converting at least one prodrug tothe active form of the drug.

The enzymatic or enzyme-conjugated antibody or fragment will combinedwith an initially separate formulation of the “prodrug”. The prodrugwill be an inactive or weakly active form of a drug that is that isconverted to the active form of the drug on contact with the enzymaticcapacity, converting function or enzyme associated with theanti-aminophospholipid or anti-anionic phospholipid antibody of theinvention, preferably one that competes with the monoclonal antibody 9D2or 3G4 (ATCC PTA 4545).

Accordingly, kits are provided that comprise, preferably in separatecompositions and/or containers:

-   -   (a) a biologically effective amount of at least a first        anti-aminophospholipid or anti-anionic phospholipid antibody, or        antigen-binding fragment thereof, preferably one that competes        with the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), which        has an enzymatic function, preferably where the antibody or        fragment is operatively associated with, covalently linked or        conjugated to, at least a first enzyme; and    -   (b) a biologically effective amount of at least a first        substantially inactive prodrug that is converted to a        substantially active drug by the enzymatic function of, or by        the enzyme associated with, linked to or conjugated to the        anti-aminophospholipid or anti-anionic phospholipid antibody or        fragment thereof.

Suitable enzymes that cleave a substantially inactive prodrug to releasea substantially active drug include arylsulfatase, serratia protease,thermolysin, subtilisin, a carboxypeptidase, a cathepsin,D-alanylcarboxypeptidase, β-galactosidase, neuraminidase, β-lactamase,penicillin amidase and cytosine deaminase.

Other than prodrugs, the at least a second, anti-cancer agent may be anyof the second, anti-cancer agents described above in relation to thecombined anti-cancer compositions of the invention. For treating viralinfections, the at least a second, anti-viral agent may also be any ofthe second, anti-viral agents described above in relation to thecombined anti-viral compositions of the invention. However, the “kits”may comprise the at least two recited the agents “in combination, butseparately”, thus providing even more flexibility in the selection ofagents.

The kits of the invention may therefore comprise combined biologicallyor therapeutically effective amounts of at least the two specifiedagents within a single container or container means, or within distinctcontainers or container means. The kits may also comprise instructionsfor using the biological and therapeutic agents included therein.Imaging components may also be included in combination, but separatelywith the therapeutic kits.

Anti-Angiogenic and Tumor Treatment: The present invention provides anumber of methods and uses of the anti-aminophospholipid or anti-anionicphospholipid antibodies, including the 9D2- and 3G4-like antibodies, andthe substantially cell impermeant PE-binding peptide and duramycinderivatives. Concerning all methods, the terms “a” and “an” are used tomean “at least one”, “at least a first”, “one or more” or “a plurality”of steps in the recited methods, except where specifically stated. Thisis particularly relevant to the administration steps in the treatmentmethods. Thus, not only may different doses be employed with the presentinvention, but different numbers of doses, e.g., injections orinhalations, may be used, up to and including multiple injections orinhalations.

Various useful in vitro methods and uses are provided that haveimportant biological implications. First provided are methods of, anduses in, binding aminophospholipids or anionic phospbolipids, preferablyPS or PE, which generally comprise effectively contacting a compositioncomprising an aminophospholipid or anionic phospholipid, preferably PSor PE, with at least a first anti-aminophospholipid or anti-anionicphospholipid antibody, or antigen-binding fragment thereof, preferablyan antibody that binds to substantially the same epitope as themonoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), or with a substantiallycell impermeant duramycin derivative. The “contacting” is underconditions effective to allow the formation of bound complexes, and anycomplexes so formed are detected. The detection methods and uses may beused in connection with biological samples, e.g., in diagnostics forapoptosis, tumors and virally infected cells, and diagnostic kits basedthereon are also provided.

Proliferation inhibition methods and uses are provided, which preferablyuse the antibodies, antigen binding fragments and immunoconjugates ofthe invention. Methods to inhibit endothelial cell proliferation and/ormigration generally comprise contacting a population of cells or tissuesthat includes a population of endothelial cells with a compositioncomprising a biologically effective amount of at least a firstanti-aminophospholipid or anti-anionic phospholipid antibody, optionallyone that binds to substantially the same epitope as the monoclonalantibody 9D2 or 3G4 (ATCC PTA 4545), or an antigen-binding fragmentthereof, under conditions effective to inhibit endothelial cellproliferation and/or migration.

The foregoing methods and uses can be performed in vitro and in vivo, inthe latter case, wherein the tissues or cells are located within ananimal and the anti-aminophospholipid or anti-anionic phospholipidantibody is administered to the animal. In both cases, the methods anduses become methods and uses for inhibiting angiogenesis, comprisingcontacting a population of potentially angiogenic blood vessels, or atissue comprising a population of potentially angiogenic blood vessels,with an anti-angiogenic composition comprising a biologically effectiveamount of at least a first anti-aminophospholipid or anti-anionicphospholipid antibody, optionally one that binds to substantially thesame epitope as the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), oran antigen-binding fragment thereof, under conditions effective toinhibit angiogenesis.

Where populations of potentially angiogenic blood vessels are maintainedex vivo, the present invention has utility in drug discovery programs.In vitro screening assays, with reliable positive and negative controls,are useful as a first step in the development of drugs to inhibit orpromote angiogenesis, as well as in the delineation of furtherinformation on the angiogenic process. Where the population ofpotentially angiogenic blood vessels is located within an animal orpatient, the anti-angiogenic composition is administered to the animalas a form of therapy.

Anti-angiogenic and anti-vascular therapies are provided in terms ofanimals and patients that have, or are at risk for developing, anydisease or disorder characterized by undesired, inappropriate, aberrant,excessive and/or pathological vascularization. It is well known to thoseof ordinary skill in the art that as aberrant angiogenesis occurs in awide range of diseases and disorders, a given anti-angiogenic therapy,once shown to be effective in any acceptable model system, can be usedto treat the entire range of diseases and disorders connected withangiogenesis.

The methods and uses of the present invention are particularly intendedfor use in animals and patients that have, or are at risk fordeveloping, any form of vascularized tumor; macular degeneration,including age-related macular degeneration; arthritis, includingrheumatoid arthritis; atherosclerosis and atherosclerotic plaques;diabetic retinopathy and other retinopathies; thyroid hyperplasias,including Grave's disease; hemangioma; neovascular glaucoma; andpsoriasis.

As disclosed in U.S. Pat. Nos. 5,712,291 and 6,524,583, specificallyincorporated herein by reference, each of the foregoing treatment groupsare by no means exhaustive of the types of conditions that are to betreated by the present invention. U.S. Pat. Nos. 5,712,291 and 6,524,583are incorporated herein by reference for certain specific purposes,including the purpose of identifying a number of other conditions thatmay be effectively treated by an anti-angiogenic therapeutic; thepurpose of showing that the treatment of all angiogenic diseasesrepresents a unified concept, once a defined category ofangiogenesis-inhibiting compounds have been disclosed and claimed (inthe present case, anti-aminophospholipid or anti-anionic phospholipidantibodies, optionally those that bind to substantially the same epitopeas the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545)); and the purposeof showing that the treatment of all angiogenic diseases is enabled bydata from only a single model system.

In addition to the treatment of angiogenic and vascular diseases,important and unified aspects of the present invention are compositionsand methods for treating cancer. Such methods comprise administering toan animal or patient that has, or is at risk for developing, cancer, abiologically or therapeutically effective amount of at least a firstcomposition comprising at least a first purified anti-aminophospholipidor anti-anionic phospholipid antibody, or antigen-binding fragment orimmunoconjugate thereof, preferably one that binds to essentially thesame epitope as, or competes with, the monoclonal antibody 9D2 or 3G4(ATCC PTA 4545), or a substantially cell impermeant PE-binding peptidederivative, preferably a substantially cell impermeant duramycinderivative.

The cancer treatment methods of the invention, even those using theantibodies, do not rely solely on exerting anti-vascular and/oranti-angiogenic effects. The cancer treatment methods and uses of theinvention are suitable for treating all forms of cancer, includinganimals and patients that have, or are at risk for developing, avascularized solid tumor, a metastatic tumor or metastases from aprimary tumor. The methods of the invention preferably exert ananti-cancer effect without causing significant thrombotic complications.

Both unconjugated or naked antibodies, and fragments thereof, andimmunoconjugates may be used in the cancer treatment aspects of theinvention. As to the use of immunoconjugates, the invention providesmethods for delivering selected therapeutic or diagnostic agents totumors. Such embodiments comprise administering to an animal or patienthaving a tumor a biologically effective amount of a compositioncomprising at least a first immunoconjugate in which a diagnostic ortherapeutic agent is operatively attached to an anti-aminophospholipidor anti-anionic phospholipid antibody, or antigen-binding fragmentthereof, preferably one that binds to substantially the same epitope as,or competes with, the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545).

The invention therefore provides tumor diagnostic, prognostic, imagingand related methods using an anti-aminophospholipid or anti-anionicphospholipid antibody, or antigen-binding fragment thereof, preferablyone that binds to substantially the same epitope as, or competes with,the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), to detectpre-apoptotic and apoptotic cells. Such methods can be used as asurrogate marker to monitor the progress of other treatment,particularly chemotherapy, or to form an image of a tumor prior totreatment.

The use of the invention as a surrogate marker to monitor the progressof cancer treatment, particularly chemotherapy, comprises:

-   -   (a) subjecting an animal or patient with a tumor to at least a        first treatment designed to exert an anti-tumor effect; and    -   (b) subsequently administering to the same animal or patient a        diagnostically effective amount of at least a first        anti-aminophospholipid or anti-anionic phospholipid antibody, or        antigen-binding fragment thereof, preferably one that binds to        substantially the same epitope as, or competes with, the        monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), operatively        attached to a detectable label or diagnostic agent, thereby        forming a detectable image of the tumor, preferably an image of        pre-apoptotic or apoptotic tumor cells or tumor vascular        endothelial cells within the tumor; and preferably    -   (c) analyzing the detectable image of the tumor, preferably the        image of the pre-apoptotic or apoptotic tumor cells or tumor        vascular endothelial cells within the tumor, thereby assessing        the progress or effectiveness of the at least a first treatment        designed to exert an anti-tumor effect.

The combined imaging and cancer treatment methods comprise:

-   -   (a) forming an image of a tumor by administering to an animal or        patient having a tumor a diagnostically minimal or effective        amount of at least a first anti-aminophospholipid or        anti-anionic phospholipid antibody, or antigen-binding fragment        thereof, preferably one that binds to substantially the same        epitope as, or competes with, the monoclonal antibody 9D2 or 3G4        (ATCC PTA 4545), operatively attached to a detectable label or        diagnostic agent, thereby forming a detectable image of the        tumor; and    -   (b) subsequently administering to the same animal or patient a        therapeutically optimized or effective amount of at least a        first anti-aminophospholipid or anti-anionic phospholipid        antibody, or antigen-binding fragment or immunoconjugate        thereof, preferably one that binds to essentially the same        epitope as, or competes with, the monoclonal antibody 9D2 or 3G4        (ATCC PTA 4545), thereby causing an anti-tumor effect.

For use in the cancer treatment methods of the invention, the currentlypreferred antibodies are those that bind to substantially the sameepitope as, or compete with, the monoclonal antibody 9D2 and 3G4 (ATCCPTA 4545). In terms of immunoconjugates, anti-aminophospholipid oranti-anionic phospholipid antibodies, preferably those that compete withthe monoclonal antibody 9D2 and 3G4 (ATCC PTA 4545), linked to ananti-cancer agent from Table E or Table F, a combretastatin, gelonin,TNFα, IL-12 and LEC are currently preferred. The currently preferredsubstantially cell impermeant PE-binding peptide derivatives use incancer treatment are duramycin derivatives, most preferably duramycinlinked to biotin or duramycin linked to HIgG.

Within the antibody-based cancer treatment methods of the invention, theinvention further provides prodrug treatment methods, which generallycomprise:

-   -   (a) administering to an animal or patient with a tumor a first        pharmaceutical composition comprising a first        anti-aminophospholipid or anti-anionic phospholipid antibody, or        antigen-binding fragment thereof, preferably one that competes        with the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), which        antibody or fragment thereof has an enzymatic function,        preferably where the antibody or fragment is operatively        associated with, covalently linked or conjugated to, at least a        first enzyme; wherein the antibody or fragment localizes to the        tumor after administration and    -   (b) subsequently administering to the animal or patient, after        an effective time period, at least a second pharmaceutical        composition comprising a biologically effective amount of at        least one substantially inactive prodrug; wherein the prodrug is        converted to a substantially active drug by the enzymatic        function of, or by the enzyme associated with, linked to or        conjugated to the anti-aminophospholipid or anti-anionic        phospholipid antibody, or fragment thereof, localized within the        tumor.

The present invention further provides a range of combination cancertreatment methods, comprising administering to an animal or patient withcancer a therapeutically effective combined amount of at least a firstpurified anti-aminophospholipid or anti-anionic phospholipid antibody,or antigen-binding fragment or immunoconjugate thereof, optionally onethat binds to essentially the same epitope as the monoclonal antibody9D2 or 3G4 (ATCC PTA 4545), or a substantially cell impermeantPE-binding peptide derivative, preferably a substantially cellimpermeant duramycin derivative, and at least a second, distincttherapeutic or anti-cancer agent.

Generally speaking, the at least a second anti-cancer agent may beadministered to the animal or patient before, during or afteradministration of the anti-aminophospholipid or anti-anionicphospholipid antibody, 9D2- or 3G4-based therapeutic or substantiallycell impermeant duramycin derivative. The at least a second anti-canceragent may be administered to the animal or patient “substantiallysimultaneously” with the anti-aminophospholipid or anti-anionicphospholipid antibody, 9D2- or 3G4-based therapeutic or substantiallycell impermeant duramycin derivative; such as from a singlepharmaceutical composition or from two pharmaceutical compositionsadministered closely together.

Alternatively, the at least a second anti-cancer agent may beadministered to the animal or patient at a time sequential to theadministration of the anti-aminophospholipid or anti-anionicphospholipid antibody, 9D2- or 3G4-based therapeutic or substantiallycell impermeant duramycin derivative. “At a time sequential”, as usedherein, means “staggered”, such that the at least a second anti-canceragent is administered to the animal or patient at a time distinct to theadministration of the anti-aminophospholipid or anti-anionicphospholipid antibody, 3G4-based therapeutic or substantially cellimpermeant duramycin derivative.

In sequential administration, the two agents are administered at timeseffectively spaced apart to allow the two agents to exert theirrespective therapeutic effects, i.e., they are administered at“biologically effective time intervals”. The at least a secondanti-cancer agent may be administered to the animal or patient at abiologically effective time prior to the anti-aminophospholipid oranti-anionic phospholipid antibody, 9D2- or 3G4-based therapeutic orsubstantially cell impermeant duramycin derivative, or at a biologicallyeffective time subsequent to that therapeutic.

Any therapeutic or anti-cancer agent may be used as the second,therapeutic or anti-cancer agent in the combined cancer treatmentmethods of the invention including any of the therapeutic or anti-canceragents described above in relation to the anti-cancer compositions andkits of the invention. Preferred agents are those that complement orenhance the therapeutic effects of the antibodies, fragments,immunotoxins or peptide derivatives, such as vascular permeabilityenhancing agents, anti-angiogenic agents, apoptosis-inducing agents,calcium flux inducing agents, inflammatory cytokines, antibodies andimmunotoxins to tumor cells and necrotic tumor cells, chemotherapeuticagents from Table E or Table F, a combretastatin, doxorubicin, etoposideand actinomycin-D.

Docetaxel is a particularly preferred agent for use in combinationtherapy. Docetaxel may be administered separately to theanti-aminophospholipid or anti-anionic phospholipid antibody,substantially cell impermeant PE-binding peptide or duramycinderivative, either before or afterwards. As to simultaneousadministration, docetaxel may be given in separate or the sameformulations, optionally within a liposome or stealthed liposome, andpreferably within the core of a stealthed liposome coated with anantibody that binds to an aminophospholipid or anionic phospholipid,preferably an antibody that binds to essentially the same epitope as, orcompetes with, the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545).

Treating Viral Infections: Particularly important and surprisingdevelopments of the invention concern antibodies, immunoconjugates,peptides, peptide conjugates, compositions, combinations, kits, methods,uses and medicaments for inhibiting viruses and for treating orpreventing viral infections. In a first instance, the anti-viral methodsof the invention concern contacting a composition comprising, orpopulation of cells or tissue(s) that contains or is suspected tocontain, a virally infected cell with at least a first compositioncomprising a biologically effective amount of at least a first purifiedantibody that binds to an aminophospholipid or anionic phospholipid,preferably to PS or PE, optionally one that binds to essentially thesame epitope as, or competes with, the monoclonal antibody 9D2 or 3G4(ATCC PTA 4545), or antigen-binding fragment, immunoconjugate oranti-viral conjugate thereof, or a substantially cell impermeantPE-binding peptide derivative, preferably a substantially cellimpermeant duramycin derivative, or an anti-viral conjugate thereof. Thevirally infected cell is preferably a eukaryotic cell, such as an animalcell, and preferably a mammalian or human cell.

The anti-viral methods and uses can be performed in vitro and in vivo.In the in vitro embodiments, the methods have important utilities. Forexample, in drug discovery programs for the development of anti-viraldrugs or combinations thereof, as well as in the delineation of furtherinformation on viral infection, replication and spread. The in vitroanti-viral methods may also be used in purging viruses from biologicalsamples, such as cell populations and tissue cultures for laboratoryuse, from samples, tissues, seeds, plant parts and plants foragricultural use, and from blood and tissue samples for therapeutic use.In the in vivo methods, where the cells, populations or tissues arelocated within an animal, the anti-aminophospholipid or anti-anionicphospholipid antibody, fragment, immunoconjugate, substantially cellimpermeant PE-binding peptide, duramycin derivative or anti-viralconjugate thereof, is administered to the animal as anti-viral therapy.

In both cases, the compositions, methods and uses inhibit one or moresteps or stages necessary for a productive or ongoing viral infection,including inhibiting viral entry. Preferably, the compositions, methodsand uses inhibit viral replication and/or spread, such as inhibiting oneor more steps of viral transcription, translation, assembly, packagingand/or egress within or from an infected host cell, such as a mammalianor human cell. The invention therefore preferably limits orsubstantially confines viral infections to initially infected cells andcell populations, thus substantially inhibiting or preventing thesubsequent or ongoing infection of additional host cells or tissues.

The anti-viral treatment methods of the invention preferably concernadministering to an animal or patient having, suspected of having or atrisk for developing a viral infection or associated disease at least afirst composition comprising a biologically effective amount of at leasta first purified antibody that binds to an aminophospholipid or anionicphospholipid, preferably to PS or PE, optionally one that binds toessentially the same epitope as, or competes with, the monoclonalantibody 9D2 or 3G4 (ATCC PTA 4545), or antigen-binding fragment,immunoconjugate or anti-viral conjugate thereof, or a substantially cellimpermeant PE-binding peptide derivative, preferably a substantiallycell impermeant duramycin derivative, or an anti-viral conjugatethereof.

Currently preferred therapeutic agents for use in anti-viral treatmentare antibodies that bind to an aminophospholipid, preferably to PS orPE, and immunoconjugates of such antibodies operatively attached to atleast a second, distinct anti-viral agent; duramycin peptides andderivatives linked to biotin or linked to HIgG, and conjugates ofPE-binding peptides, preferably duramycins, operatively linked to atleast a second, distinct anti-viral agent. Suitable anti-viral agentsfor attachment to the antibodies and peptides include those set forth inTable G, such as AZT or cidofovir.

As the invention inhibits one or more steps or stages necessary forproductive or ongoing infection common to all viruses, the anti-viralmethods and uses of the invention are suitable for treating all viruses,both enveloped and non-enveloped viruses, including those that infectplants, animals, vertebrates, mammals and human patients. The inventionis suitable for treating all viruses that infect vertebrates, as listedherein in Table H, particularly humans, and particularly viruses thatare pathogenic in animals and humans. The viral infections andassociated and resultant diseases that can be treated by the inventioninclude those viruses and diseases set forth in Table J, as exemplifiedby treating CMV, RSV, arenavirus and HIV infections, and the diseaseshepatitis, influenza, pneumonia, Lassa fever and AIDS.

The anti-viral treatment methods of the invention may also be used incombination with other therapeutics and diagnostics. The combinedtreatment methods comprise administering to an animal or patient with aviral infection a therapeutically effective combined amount of at leasta first composition comprising at least a first purified antibody thatbinds to an aminophospholipid or anionic phospholipid, preferably to PSor PE, optionally one that binds to essentially the same epitope as, orcompetes with, the monoclonal antibody 9D2 or 3G4 (ATCC PTA 4545), orantigen-binding fragment, immunoconjugate or anti-viral conjugatethereof, or a substantially cell impermeant PE-binding peptidederivative, preferably a substantially cell impermeant duramycinderivative, or an anti-viral conjugate thereof, and at least a second,distinct therapeutic or anti-viral agent.

The at least a “second, distinct” anti-viral agent is in reference tothe anti-aminophospholipid or anti-anionic phospholipid antibody,fragment or immunoconjugate, or substantially cell impermeant PE-bindingpeptide, duramycin derivative or anti-viral conjugate thereof, being the“first” anti-viral agent. The at least a second anti-viral agent may beadministered to the animal or patient during administration of, orsubstantially simultaneously with, the first anti-viral agent of theinvention; or before or after, i.e., sequential to the administration ofthe first anti-viral agent of the invention.

Any therapeutic or anti-viral agent may be used as the secondtherapeutic or anti-viral agent in the combined anti-viral treatmentmethods of the invention, including any of the anti-viral agentsdescribed above in relation to the anti-viral conjugates, compositionsand kits of the invention.

The foregoing cancer and anti-viral treatment methods and uses willoften involve the administration of the pharmaceutically effectivecomposition to the animal or patient systemically, such as bytransdermal, intramuscular, intravenous injection and the like. Fortreating viral infections, particularly respiratory viral infections,delivery to the lung is another preferred embodiment, as may be achievedusing an aerosol. However, any route of administration that allows thetherapeutic agent to localize to the site of the tumor or viralinfection will be acceptable. Therefore, other suitable routes ofdelivery include oral, rectal, nasal, topical, and vaginal. For uses andmethods for the treatment of arthritis, e.g., intrasynovialadministration may be employed, as described for other immunologicalagents in U.S. Pat. No. 5,753,230, specifically incorporated herein byreference. For conditions associated with the eye, ophthalmicformulations and administration are contemplated.

“Administration”, as used herein, means provision or delivery ofanti-aminophospholipid or anti-anionic phospholipid antibody or 9D2- or3G4-based therapeutics, or substantially cell impermeant PE-bindingpeptide derivatives, preferably duramycin derivatives in an amount(s)and for a period of time(s) effective to exert a therapeutic effect. Thepassive administration of proteinaceous therapeutics is generallypreferred, in part, for its simplicity and reproducibility.

However, the term “administration” is herein used to refer to any andall means by which the therapeutics are delivered. “Administration”therefore includes the provision of cells that produce theanti-aminophospholipid or anti-anionic phospholipid antibody, 3G4-basedor duramycin derivative therapeutics in an effective manner. In suchembodiments, it may be desirable to formulate or package the cells in aselectively permeable membrane, structure or implantable device,generally one that can be removed to cease therapy. Exogenousadministration will still generally be preferred, as this represents anon-invasive method that allows the dose to be closely monitored andcontrolled.

The therapeutic methods and uses of the invention also extend to theprovision of nucleic acids that encode anti-aminophospholipid oranti-anionic phospholipid antibody, 3G4-based or duramycin derivativetherapeutics in a manner effective to result in their expression invivo. Any gene therapy technique may be employed, such as naked DNAdelivery, recombinant genes and vectors, cell-based delivery, includingex vivo manipulation of patients' cells, and the like. Liposomes andstealthed liposomes will be preferred for use in some embodiments.

The pharmaceutical compositions and treatment methods of the inventionemploy “therapeutically effective amounts” of an anti-aminophospholipidor anti-anionic phospholipid antibody, optionally one that binds tosubstantially the same epitope as the monoclonal antibody 9D2 or 3G4(ATCC PTA 4545), or an antigen-binding fragment or immunoconjugate ofsuch an antibody, or a substantially cell impermeant PE-binding peptidederivative, preferably a substantially cell impermeant duramycinderivative, or an anti-viral conjugate thereof. The “therapeuticeffects” and consequent “therapeutically effective amounts” are measuredby different parameters in cancer treatment vs. anti-viral treatment.

In cancer treatment, the amounts of the agents are effective tospecifically kill at least a portion of tumor cells, tumor orintratumoral vascular endothelial cells; to specifically induceapoptosis in at least a portion of tumor cells, tumor or intratumoralvascular endothelial cells; to specifically promote coagulation in atleast a portion of tumor or intratumoral blood vessels; to specificallyocclude or destroy at least a portion of blood transporting vessels ofthe tumor; to specifically induce necrosis in at least a portion of atumor; and/or to induce tumor regression or remission uponadministration to an animal or patient.

In treating viral infections and related diseases, the amounts of theagents are effective to inhibit one or more requirements for ongoingviral infection, such as viral entry, and preferably, viral replication,egress and spread from the infected host cells. The amounts may alsokill or remove at least a portion of the virally infected cells in amanner that counteracts viral replication, spread and ongoing infection.Overall, the amounts of the agents are effective to reduce,significantly reduce or eradicate the viral infection uponadministration to an animal or patient.

The terms “preferentially” and “specifically”, as used herein, mean thatthe anti-aminophospholipid or anti-anionic phospholipid antibody,3G4-based therapeutics, or substantially cell impermeant PE-bindingpeptide derivatives, preferably duramycin derivatives, achieveanti-cancer or anti-viral effects that are substantially confined to thedisease site, and do not substantially cause coagulation, destructionand/or tissue necrosis in normal, healthy tissues of the animal orsubject. The structure and function of healthy cells and tissues istherefore maintained substantially unimpaired by the practice of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings form part of the present specification and areincluded to further demonstrate certain aspects of the presentinvention. The invention may be better understood by reference to one ormore of these drawings in combination with the detailed description ofspecific embodiments presented herein.

FIG. 1. Localization of anti-PS antibody (3SB) to vascular endothelialcells in L540 human Hodgkin's lymphoma, 3LL murine lung carcinoma andB16 murine melanoma tumors in mice. Tumor-bearing SCID mice wereinjected intravenously with 20 μg of anti-PS (3SB) or anti-CL (D11)mouse IgM. The blood circulation was perfused with saline 1 h later.Mice were sacrificed 1 h later and tumor and organs were harvested andsnap-frozen. Mouse IgM was detected on frozen sections using goatanti-mouse IgM-peroxidase conjugate. Anti-PS antibody specificallylocalized to blood vessels (indicated by arrows) in all tumors. Nolocalization was observed in mice injected with control, anti-CL IgM.

FIG. 2A and FIG. 2B. Binding of 9D2 antibody and annexin V tophospholipids adsorbed to plastic. Phospholipids were adsorbed toplastic of microtiter plates. After blocking with 10% serum, 9D2antibody (FIG. 2A) or annexin V (FIG. 2B) were added at concentrationsranging from 6.66 nM to 0.005 nM in the presence of 10% serum. Theplates were washed and the bound 9D2 antibody and annexin V weredetected using goat anti-rat IgM-HRP and rabbit anti-annexin V IgGfollowed by anti-rabbit-HRP, respectively.

FIG. 3. Inhibition of binding of 9D2 antibody and annexin V to anionicphospholipids on H₂O₂-treated endothelial cells with competingphospholipid liposomes. 9D2 antibody and annexin V (6.66 nM) werepre-incubated with various phospholipid liposomes (200 μg/ml) DPBSbuffer containing 10% serum. The bound 9D2 antibody and annexin V weredetected using goat anti-rat IgM-HRP and rabbit anti-annexin V IgGfollowed by anti-rabbit-HRP respectively. Binding in the presence orabsence of competing liposomes was determined. Standard deviations oftriplicate measurements were less than 10% of the mean values.

FIG. 4. Localization of biotinylated 9D2 antibody and annexin V tovascular endothelial cells and tumor cells in orthotopic MDA-MB-231human breast tumors in mice. Nu/nu mice bearing MDA-MB-231 tumors intheir mammary fat pads were injected intravenously with 50 μg ofbiotinylated 9D2 antibody or 100 μg of biotinylated annexin V. One hlater, their blood circulation was perfused with saline. Tumor andorgans were removed and snap-frozen. Localized 9D2 and annexin V weredetected on the frozen sections using streptavidin-HRP conjugate. Tumorsections derived from mice injected with saline or control rat IgMserved as negative controls.

FIG. 5. Combined effects of hypoxia and inflammatory cytokines on PSexposure, bEnd.3 cells were treated for 24 h with IL-1α and TNFα undernormoxic (white bars) and hypoxia (gray bars) conditions. The cellmonolayers remained intact and viable under these conditions. PSexternalization was determined by measuring binding of ¹²⁵I-annexin V.The level of PS exposure was expressed as a percentage of that in cellstreated with combination of actinomycin D and TNFα.

FIG. 6A and FIG. 6B. Anti-tumor effects of anti-PS antibody (3SB) inanimals with syngeneic and xenogeneic tumors. 1×10⁷ cells of murinecolorectal carcinoma Colo 26 (FIG. 6A) or human Hodgkin's lymphoma L540(FIG. 6B) were injected subcutaneously into the right flank of BALB/cmice (FIG. 6A) or male CB 17 SCID mice (FIG. 6B), respectively. Tumorswere allowed to grow to a size of about 0.6-0.9 cm³ and then the mice (4animals per group) were injected i.p. with 20 μg of naked anti-PSantibody (open squares) or saline (open circles). Treatment was repeated3 times with a 48 hour interval. Animals were monitored daily for tumormeasurements and body weight. Mice were sacrificed when tumors hadreached 2 cm³, or earlier if tumors showed signs of necrosis orulceration. Control mouse IgM gave similar results to saline.

FIG. 7. Anti-tumor effects of 9D2 antibody in mice bearing L540 humanHodgkin's lymphoma. Groups of tumor-bearing mice were injected with 100μg of 9D2 antibody (closed circles) intraperitoneally 3 times per week,as opposed to control (open squares). The tumor size was taken bycalipers twice a week. The tumor volume is plotted against the number ofdays after tumor cell injections. The numbers in parentheses indicatenumber of mice with regressed tumors/total number of mice per group.

FIG. 8A, FIG. 8B, FIG. 8C, FIG. 8D, FIG. 8E, FIG. 8F and FIG. 8G.Anti-tumor effects of anti-PS antibody, 3G4, in animals with syngeneicand xenogeneic tumors. Cells of murine Meth A tumors (FIG. 8A), humanMDA-MB-231 breast cancer (FIG. 8B and FIG. 8E), human Hodgkin's lymphomaL540 (FIG. 8C and FIG. 8D) and MDA-MB-231 cancer (FIG. 8F and FIG. 8G)were injected into mice. Tumors were allowed to grow to the sizes shownbefore treatment. The human Hodgkin's lymphoma cells were allowed toform large tumors. Each group of mice was injected intraperitoneally 3times per week with 100 μg of 3G4 antibody as opposed to control (3G4 isstated on FIG. 8A, FIG. 8B, FIG. 8C; and shown by open circles on FIG.8D, FIG. 8E, FIG. 8F). Animals were monitored twice a week for tumormeasurements. The tumor volume is plotted against the number of daysafter tumor inoculation (FIG. 8A) or against the days of treatment (FIG.8B and FIG. 8C) for 20-30 days (FIG. 8A, FIG. 8B and FIG. 8C; numbers inparentheses indicate number of mice with regressed tumors/total numberof mice per group) or 60 days (FIG. 8D, FIG. 8E and FIG. 8F). The 3G4antibody and chimeric 3G4 antibody (ch3G4) were used to treat MDA-MB-231cancer cells, as opposed to control (FIG. 8G).

FIG. 9A and FIG. 9B. Inhibition of CMV replication in vitro by 3G4antibody. CMV-infected HHF-R2 cells were treated with 3G4 (top twopanels). The control wells were left untreated (bottom two panels) orwere treated with the isotype matched control IgG₃ antibody GV39G(middle two panels). Cells were observed at different time points: day 3(left column) and day 9 (right column). Infected cells appear greenunder the fluorescent microscope. Antibody treatment at 100 μg/ml (FIG.9A) and 50 μg/ml (FIG. 9B).

FIG. 10. Concentration dependent inhibition of CMV replication in vitro.CMV-infected HHF-R2 cells were treated with different concentrations of3G4 (top panels). The control wells were left untreated (bottom panel)or were treated with the isotype matched control IgG₃ antibody GV39G(middle panels). Cells were observed on day 9. Infected cells appeargreen under the fluorescent microscope.

FIG. 11A, FIG. 11B and FIG. 11C. Quantification of CMV viral load inantibody-treated cells and inhibition of replication at a late stage ofthe viral replication cycle. Monolayers of human fibroblasts wereinfected with CMV at a low m.o.i, of 0.01 pfu/cell and treated with theindicated concentrations of the 3G4 antibody; the control antibody,GV39G; or the control anti-colchicine antibody, C44 (FIG. 11A; Untreat.,untreated control). Monolayers of human fibroblasts were infected withCMV at a high m.o.i, of 3 pfu/cell and treated with 50 μg/ml or 100μg/ml of the 3G4 antibody or the control antibody, GV39G (FIG. 11B).Monolayers of human fibroblasts were infected with CMV at a high m.o.i.,the 3G4 antibody or the control antibody, GV39G were added at theindicated time points after infection (FIG. 11C). In each of FIG. 11A,FIG. 11B and FIG. 11C, the viral load in cells and supernatants wasquantified using a standard plaque assay.

FIG. 12. Inhibition of RSV replication in vitro by 3G4, 1B9 and 3SBantibodies. RSV-infected A-549 cells were treated with 3G4, 1B9 or 3SBor left untreated as control. Treatment with 1B9 (green) and 3SB (red)resulted in a log decrease in viral replication (vs. control in blue).The even more pronounced anti-viral effect of 3G4 is shown in pink.

FIG. 13A, FIG. 13B, FIG. 13C, FIG. 13D, FIG. 13E, FIG. 13F, FIG. 13G,FIG. 13H, FIG. 13I, FIG. 13J, FIG. 13K, FIG. 13L, FIG. 13M, FIG. 13N,FIG. 13O, FIG. 13P, FIG. 13Q and FIG. 13R. Structures of duramycinderivatives. The chemical structures for exemplary duramycin derivativesfrom Example XV are depicted. In each of the compounds of FIG. 13A toFIG. 13O, the PE-binding peptide, duramycin, has been attached to a cellimpermeant group to prevent the construct from exerting significant,non-specific toxic effects. The schematic structure of the parentduramycin cyclic peptide is shown in FIG. 13P. The linear sequence isrepresented by SEQ ID NO:9, and the structures of the modified aminoacids in the sequence are depicted in FIG. 13Q. FIG. 13R depicts anexemplary duramycin anti-viral construct, in which duramycin is linkedto cidofovir.

FIG. 14A, FIG. 14B, FIG. 14C and FIG. 14D. Binding specificities ofduramycin derivatives. The duramycin derivatives were prepared asdescribed in Example XV and their specificities determined using ELISAsand competition ELISAs, as described in Example XVI. FIG. 14A,phospholipid binding profile of duramycin derivatives against a panel ofphospholipids, showing specificity for PE; FIG. 14B, serum has nosignificant effect on PE binding; FIG. 14C and FIG. 14D, results fromcompetition ELISAs confirming specificity of duramycin derivatives forPE.

FIG. 15. Inhibition of CMV replication in vitro by duramycinderivatives. CMV infected HHF-R2 cells were treated with duramycinderivatives (DLB)₄NA and (DIM)_(n)HIgG. The control wells were leftuntreated. Cells were observed at different time points: day 4 (leftpanels) and day 6 (right panels). Infected cells appear green under thefluorescent microscope. (DLB)₄NA and (DIM)_(n)HIgG inhibit viral spreadfrom singly-infected cells.

FIG. 16. Selective inhibition of dividing endothelial cells by anti-PSantibodies. The anti-PS antibodies 3SB, 9D2 and 3G4 were tested forinhibitory effects on endothelial cells in vitro as in Example XVIII.Each of the 3SB, 9D2 and 3G4 antibodies exhibit selective inhibition ofdividing (subconfluent) endothelial cells as opposed to quiescent(confluent) cells. The 9D2 and 3G4 antibodies both have a greaterinhibitory effect than 3SB.

FIG. 17A and FIG. 17B. Anti-angiogenic and vascular targeting effects ofthe 3G4 antibody in tumor-bearing mice. Nude mice bearing MDA-MB-231orthotopic tumors were treated 3 times a week with 100 μg/dose 3G4antibody (treated, right panels) or with the same dose of anisotype-matched, control antibody (control, left panels). At theconclusion of treatment, animals were perfused and tumors weresnap-frozen, cut and stained with an antibody to murine CD31 (rat,anti-mouse CD31), a pan-endothelial marker of murine vasculature (FIG.17A), or embedded in paraffin and strained with H&E (FIG. 17B).Comparing the tumor sections from the control and treated animals showsthat the administration of the 3G4 results in anti-angiogenic (FIG. 17A)and vascular targeting (FIG. 17B) effects.

FIG. 18A and FIG. 18B. DNA and amino acid sequences of the variableregions of the 3G4 antibody, encompassing complementarity determiningregions (CDRs) of the 3G4 antibody. DNA and amino acid sequences for theheavy (FIG. 18A; SEQ ID NO: 1 and SEQ ID NO:2) and light (FIG. 18B; SEQID NO:3 and SEQ ID NO:4) chains are presented, and the restriction sitesin the DNA sequences are shown. The leader sequence is distinguishedfrom the mature protein, which begins as shown by the first arrow ineach of FIG. 18A and FIG. 18B. In the heavy chain, the amino acidsequence of CDR1 is SEQ ID NO:10, CDR2 is SEQ ID NO:11 and CDR3 is SEQID NO:12. In the light chain, the amino acid sequence of CDR1 is SEQ IDNO:13, CDR2 is SEQ ID NO:14 and CDR3 is SEQ ID NO:15. Exemplary means ofgrafting each variable sequence with a human constant region are setforth, wherein the first part of the respective human constant regionsequences (SEQ ID NO:7 and SEQ ID NO:8) is shown by the second arrow ineach of FIG. 18A and FIG. 18B.

FIG. 19A and FIG. 19B. Comparison of the PS binding of the IgG anti-PSantibody, 3G4, with the IgM anti-PS antibody, 3SB. The PS binding of theIgM antibody, 3SB (♦) and two IgG antibodies, 3G4 (▴) and 3B10 (▪), wasdetermined by ELISA using antibody concentrations up to 3.375 nM (FIG.19A). The PS binding of the 3SB (♦), 3G4 (▴) and 3B10 (▪) antibodies atconcentrations of up to 0.06 nM is shown separately (FIG. 19B).

FIG. 20. Inhibition of binding of 3G4 antibody to immobilized PS usingcompeting phospholipid liposomes. The 3G4 antibody (0.1 μg/ml) waspre-incubated for 30 minutes with various liposomes made from purephospholipids (PS-L, PE-L, PI-L, PC-L, CL-L, PA-L and PG-L) or bufferalone (control). The mixtures were then added to PS-coated ELISA plates,washed and bound antibodies were detected using secondary antibodies andOPD. Binding in the presence of the listed liposomes is shown andcompared to 3G4 antibody binding in the absence of any liposome.

FIG. 21. Binding of chimeric 3G4 to phospholipids. The chimeric 3G4antibody (ch3G4) was prepared as described in Example XIX. Phospholipids(PS, PI, PE, PC, SM, CL, PG and PA) were adsorbed to plastic ofmicrotiter plates. After blocking, chimeric 3G4 antibody was added atthe concentrations shown. The plates were washed and the bound chimeric3G4 antibody was detected via secondary antibody binding anddevelopment.

FIG. 22. Localization of chimeric 3G4 to tumor vascular endothelium invivo. Biotinylated ch3G4 (top panels) and control IgG (bottom panels)were administered to mice bearing MD-MBA-435s tumors. Tumor sectionswere stained with Cy3-conjugated streptavidin to detect the biotinylatedantibodies (left panels). Staining with the MECA 32 antibody followed byFITC-tagged anti-rat IgG secondary antibody was conducted to detectvascular endothelium (middle panels). The red and green images aremerged (right panels), whereupon biotinylated proteins bound to thetumor vascular endothelium appear yellow. The coincident staining of thelocalized 3G4 antibody and the MECA 32 marker of the vascularendothelium is shown by the yellow color on the superimposed images (topright).

FIG. 23. Enhancement of macrophage phagocytosis of PS-positive cells by3G4. HL-60 tumor cells were labeled with the green fluorescent dye CFDA,and PS exposure was induced by 200 μM H₂O₂. Treated cells were harvestedand opsonized for 1 hr using 5 μg/mil 3G4 or an isotype-matched controlantibody (BBG3). Target cells were then added to macrophages, which wereisolated from mouse bone marrow and cultured in chamber slides for 5days in media containing 5 ng/ml GM-CSF. After 2 hrs, the slides werefixed and phagocytosis was visually counted under the fluorescentmicroscope. Results are presented as the percentage of phagocytosingmacrophages (macrophages that have phagocytosed at least one tumorcell).

FIG. 24A and FIG. 24B. Induction of PS exposure on endothelial cells bydocetaxel. Human umbilical vein endothelial cells (HUVEC) and humanmicrovessel endothelial cells (HMVEC) were treated with 10 nM ofdocetaxel for 24 hrs. Cells were harvested, washed with PBS andincubated with 3G4 at 10 μg/ml for 30 mins, on ice. The cells were thenwashed twice, FITC labeled goat anti-mouse IgG was added and the cellsincubated for a further 30 mins, on ice. The cells were then washed andanalyzed by FACS using a FACSCalibur cytometer (Becton-Dickinson, SanJose, Calif.) with CellQuest acquisition software. Both treated HUVEC(FIG. 24A) and HMVEC (FIG. 24B) show significant increases in 3G4binding as compared to untreated cells.

FIG. 25A, FIG. 25B and FIG. 25C. Induction of PS exposure on tumor celllines by docetaxel. Mouse lewis lung carcinoma 3LL, mouse coloncarcinoma Colo26 and human breast cancer MDA-MB-435 cells were treatedwith 10 nM of docetaxel for 24 hrs. Cells were harvested, washed withPBS and incubated with 3G4 at 10 μg/ml for 30 mins, on ice. The cellswere then washed twice, FITC labeled goat anti-mouse IgG was added andthe cells incubated for a further 30 mins, on ice. The cells were thenwashed and analyzed by FACS using a FACSCalibur cytometer(Becton-Dickinson, San Jose, Calif.) with CellQuest acquisitionsoftware. The treated 3LL (FIG. 25A), Colo26 (FIG. 25B) and MDA-MB-435cells (FIG. 25C) show significant increases in 3G4 binding as comparedto untreated cells.

FIG. 26. Induction of PS exposure on human breast cancer MDA-MB-231cells by docetaxel. Human breast cancer MDA-MB-231 cells were treatedwith 10 nM of docetaxel for 24 hrs. Cells were harvested, washed withPBS and incubated with chimeric 3G4 (ch3G4) or control, human IgG for 30mins, on ice. The cells were then washed twice, FITC labeled anti-IgGwas added and the cells analyzed by FACS, as above. There is asignificant increase in ch3G4 binding as compared to control, human IgG.

FIG. 27. Treatment with anti-PS antibodies increases survival ofmCMV-infected mice. Balb/C mice were infected with mCMV and treated with3G4 or ch3G4 as described in Example XXI. The mice were monitored forsurvival past 90 days after infection.

FIG. 28. Treatment with the duramycin-biotin derivative, DLB increasessurvival of mCMV-infected mice. Balb/C mice were infected with mCMV andtreated with DLB as described in Example XXII. The mice were monitoredfor survival past 90 days after infection.

FIG. 29A and FIG. 29B. Binding of chimeric 3G4 to cells infected withVaccinia virus. U937 cells were infected with Vaccinia virus and stainedwith the chimeric 3G4 antibody (ch3G4) or control human IgG (HIgG) onday 2 after infection. FIG. 29A, uninfected U-937 cells. FIG. 29B,Vaccinia virus-infected U937 cells. The peaks in FIG. 29A and FIG. 29Bare: left (red) peak, secondary antibody alone control; middle (blue)peak, control HIgG; right (green) peak, ch3G4.

FIG. 30A, FIG. 30B, FIG. 30C and FIG. 30D. Inhibition of Pichinde virusreplication in vitro by 3G4 antibody. Vero cells were infected withPichinde virus at an m.o.i, of 0.01 pfu/cell. The infected cells weretreated with 100 μg/ml of 3G4 (FIG. 30A) or isotype-matched controlantibody, GV39G (FIG. 30B). On day 2 after infection, the cells wereharvested with trypsin and allowed to adhere to slides. The cells werefixed with acetone, and stained with anti-PIC rabbit polyclonal serumfollowed by goat anti-rabbit biotin conjugated secondary antibody.Infected cells are stained red-brown. Secondary antibody alone producedno staining (FIG. 30C). The % infected cells in the 3G4 vs. controltreated cells is also shown (FIG. 30D).

FIG. 31. Duramycin-Human IgG (HIgG) conjugate inhibits MethA tumorgrowth in vivo. BALB/c mice bearing MethA tumor cells were treated withthe duramycin-HIgG conjugate (D-SIAB)_(n)HIgG, in which duramycin isconjugated to HIgG using the SIAB linker, or with control HIgG asdescribed in Example XXV.

FIG. 32. Duramycin conjugate is not cytotoxic. The naturally occurringduramycin compound and the biotinylated duramycin construct, DLB weretested for cytotoxic effects on human umbilical vein endothelial cells(HUVEC) using an MTT assay.

FIG. 33. Duramycin-antibody conjugate enhances macrophage phagocytosisof apoptotic cells. A duramycin-antibody conjugate was constructed bylinking duramycin to C44, a mouse IgG_(2a) antibody, to createduramycin-C44 (DuC44). Apoptotic HL-60 cells were incubated with mousebone-marrow derived macrophages in the presence of DuC44, a controlmouse antibody, BBG3 and the 3G4 antibody. Phagocytosis was evaluated aspercent phagocytes positive for uptake. Data are mean values±S.E.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Solid tumors and carcinomas account for more than 90% of all cancers inman. Although the use of monoclonal antibodies and immunotoxins has beeninvestigated in the therapy of lymphomas and leukemias (Vitetta et al.,1991), these agents have been disappointingly ineffective in clinicaltrials against carcinomas and other solid tumors (Abrams and Oldham,1985). A principal reason for the ineffectiveness of antibody-basedtreatments is that macromolecules are not readily transported into solidtumors. Even once within a tumor mass, these molecules fail todistribute evenly due to the presence of tight junctions between tumorcells, fibrous stroma, interstitial pressure gradients and binding sitebarriers (Denekamp, 1990; Dvorak et al., 1991).

In developing new strategies for treating solid tumors, the methods thatinvolve targeting the vasculature of the tumor, rather than the tumorcells, offer distinct advantages. An effective destruction or blockadeof the tumor vessels arrests blood flow through the tumor, resulting inan avalanche of tumor cell death. Antibody-toxin and antibody-coagulantconstructs, examples of VTA which selectively destroy and/or occludetumor blood vessels, have already been used to great effect in thespecific targeting and destruction of tumor vasculature, resulting intumor necrosis (Burrows et al., 1992; Burrows and Thorpe, 1993; WO93/17715; WO 96/01653; Huang et al., 1997; each incorporated herein byreference).

VTAs exert their primary action on the pre-existing blood vessels ofsolid tumors, and differ from anti-angiogenic agents that prevent newblood vessel formation. There are numerous advantages of VTAs over othercancer therapies. First, a single vessel provides the nutrition for andfacilitates removal of waste products of metabolism from hundreds orthousands of tumor cells, and only has to be damaged at one point toblock blood flow upstream and downstream. VTAs are thus particularlyeffective on established tumors. Second, endothelial cell killing,although one useful mechanism, is not required. A change of shape orlocal initiation of blood coagulation can be sufficient. Third, theendothelial cell is adjacent to the blood stream, ensuring adequate drugdelivery. Fourth, the target is a normal diploid cell that is unlikelyto acquire genetic mutations that render it drug resistant. Fifth, asurrogate marker of biological activity, i.e., blood flow, ismeasurable.

Sixth, temporary effects on vascular function may be sufficient forsignificant anti-tumor effects. Studies indicate that over 99% of tumorcells in vivo can be killed during a 2 hour period of ischemia. Finally,unlike angiogenesis inhibitors, VTAs only require intermittentadministration to synergize with conventional treatments, rather thanchronic administration over months or years.

Cytotoxic VTAs are described in the following patents: U.S. Pat. Nos.5,660,827, 5,776,427, 5,855,866, 5,863,538, 5,965,132, 6,004,554,6,051,230, 6,261,535 and 6,451,312, each incorporated herein byreference. Where antibodies, growth factors or other binding ligands areused to specifically deliver a coagulant to the tumor vasculature, suchagents are termed “coaguligands”. Coaguligand VTAs are described in thefollowing patents: U.S. Pat. Nos. 6,093,399, 6,004,555, 5,877,289 and6,036,955, each incorporated herein by reference.

A currently preferred coagulant for use in coaguligands is truncatedTissue Factor (tTF) (Huang et al., 1997; WO 96/01653; U.S. Pat. No.5,877,289). TF is the major initiator of blood coagulation (Ruf et al.,1991; Edgington et al., 1991). At sites of injury, Factor VII/VIIa inthe blood comes into contact with, and binds to, TF on cells in theperivascular tissues. The TF:VIIa complex, in the presence of thephospholipid surface, activates factors IX and X. This, in turn, leadsto the formation of thrombin and fibrin and, ultimately, a blood clot(Ruf and Edgington, 1994).

The recombinant, truncated form of tissue factor (tTF), lacking thecytosolic and transmembrane domains, is a soluble protein that has aboutfive orders of magnitude lower coagulation inducing ability than nativeTF (Stone et al., 1995; Huang et al., 1997). This is because TF needs tobe associated with phospholipids for the complex with VIIa to activateIXa or Xa efficiently. However, when tTF is delivered to tumor vascularendothelium by means of a targeting antibody or agent, it is broughtback into proximity to a lipid surface and regains thrombogenic activity(Huang et al., 1997; U.S. Pat. Nos. 6,093,399, 6,004,555, 5,877,289 and6,036,955). A coaguligand is thus created that selectively thrombosestumor vasculature.

Truncated TF has several advantages that commend its use in vasculartargeted coaguligands: human tTF is readily available, and the humanprotein will have negligible or low immunogenicity in man; human tTF isfully functional in experimental animals, including mice; and targetedtTF is highly potent because it triggers the activation of a cascade ofcoagulation proteins, giving a greatly amplified effect (U.S. Pat. Nos.6,093,399, 6,004,555, 5,877,289 and 6,036,955).

A range of suitable target molecules that are available on tumorendothelium, but largely absent from normal endothelium, have beendescribed. For example, expressed targets may be utilized, such asendoglin, E-selectin, P-selectin, VCAM-1, ICAM-1, PSMA, a TIE, a ligandreactive with LAM-1, a VEGF/VPF receptor, an FGF receptor, α_(v)β₃integrin, pleiotropin or endosialin (U.S. Pat. Nos. 5,855,866 5,877,289;Burrows et al., 1992; Burrows and Thorpe, 1993; Huang et al., 1997; Liuet al., 1997; Ohizumi et al., 1997; each incorporated herein byreference).

Adsorbed targets are another suitable group, such as VEGF, FGF, TGFβ,HGF, PF4, PDGF, TIMP, a ligand that binds to a TIE or a tumor-associatedfibronectin isoform (U.S. Pat. Nos. 5,877,289, 5,965,132, 6,051,230 and6,004,555). Fibronectin isoforms are ligands that bind to the integrinfamily of receptors. Tumor-associated fibronectin isoforms aretargetable components of both tumor vasculature and tumor stroma. Themonoclonal antibody BC-1 (Carnemolla et al., 1989) specifically binds totumor-associated fibronectin isoforms.

Other targets inducible by the natural tumor environment or followingintervention by man are also targetable entities, as described in U.S.Pat. Nos. 5,776,427, 5,863,538 and 6,036,955. When used in conjunctionwith prior suppression in normal tissues and tumor vascular induction,MHC Class II antigens may also be employed as targets (U.S. Pat. Nos.5,776,427, 5,863,538, 6,004,554 and 6,036,955).

One currently preferred target for clinical applications is vascularendothelial adhesion molecule-1 (VCAM-1) (U.S. Pat. Nos. 5,855,866,5,877,289, 6,051,230, 6,004,555 and 6,093,399). VCAM-1 is a celladhesion molecule that is induced by inflammatory cytokines IL-1α, IL-4(Thornhill et al., 1990) and TNFα (Munro, 1993) and whose role in vivois to recruit leukocytes to sites of acute inflammation (Bevilacqua,1993).

VCAM-1 is present on vascular endothelial cells in a number of humanmalignant tumors including neuroblastoma (Patey et al., 1996), renalcarcinoma (Droz et al., 1994), non-small lung carcinoma (Staal-van denBrekel et al., 1996), Hodgkin's disease (Patey et al., 1996), andangiosarcoma (Kuzu et al., 1993), as well as in benign tumors, such asangioma (Patey et al., 1996) and hemangioma (Kuzu et al., 1993).Constitutive expression of VCAM-1 in man is confined to a few vessels inthe thyroid, thymus and kidney (Kuzu et al., 1993; Bruijn and Dinklo,1993), and in the mouse to vessels in the heart and lung (Fries et al.,1993).

Certain of the data presented herein even further supplement thoseprovided in U.S. Pat. Nos. 5,855,866, 5,877,289, 6,051,230, 6,004,555and 6,093,399, and show the selective induction of thrombosis and tumorinfarction resulting from administration of an anti-VCAM-1·tTFcoaguligand. The results presented were generated using mice bearingL540 human Hodgkin lymphoma. When grown as a xenograft in SCID mice,this tumor shows close similarity to the human disease with respect toexpression of inflammatory cytokines (Diehl et al., 1985) and thepresence of VCAM-1 and other endothelial cell activation molecules onits vasculature.

Using a covalently-linked anti-VCAM-1-tTF coaguligand, in which tTF wasdirectly linked to the anti-VCAM-1 antibody, it is shown herein that thecoaguligand localizes selectively to tumor vessels, induces thrombosisof those vessels, causes necrosis to develop throughout the tumor andretards tumor growth in mice bearing solid L540 Hodgkin tumors. Tumorsgenerally needed to be at least about 0.3 cm in diameter to respond tothe coaguligand, because VCAM-1 was absent from smaller tumors.Presumably, in small tumors, the levels of cytokines secreted by tumorcells or host cells that infiltrate the tumor are too low for VCAM-1induction. This is in accordance with the studies in U.S. Pat. Nos.5,855,866, 5,877,289, 6,051,230, 6,004,555 and 6,093,399, where theinventions were shown to be most useful in larger solid tumors.

Although VCAM-1 staining was initially observed more in the periphery ofthe tumor, the coaguligand evidently bound to and occluded bloodtransporting vessels—as it was capable of curtailing blood flow in alltumor regions. Furthermore, one of the inventors contemplates that thethrombin generation caused by the initial administration of thecoaguligand likely leads to further VCAM-1 induction on central vessels(Sluiter et al., 1993), resulting in an amplified signal and evidentdestruction of the intratumoral region. This type of coagulant-inducedexpression of further targetable markers, and hence signalamplification, is also disclosed in U.S. Pat. No. 6,036,955.

As shown herein, although localization to VCAM-1-expressing vessels inthe heart and lungs of mice was observed upon administration of ananti-VCAM-1 coaguligand, this construct did not induce thrombosis insuch non-tumor sites. Furthermore, the anti-VCAM-1 coaguligand was nomore toxic to mice than was a control coaguligand of irrelevantspecificity, again indicating that the constitutive expression of VCAM-1on heart and lung vessels did not lead to toxicity. This data isimportant to the immediate clinical progress of coaguligand therapy,given that VCAM-1 is a naturally occurring marker of tumor vascularendothelium in humans. However, this phenomenon also provided theinventors with a unique insight, leading to a totally different approachto tumor vasculature destruction.

A. Tumor Treatment with Naked Antibodies to Aminophospholipids

The inventors sought to understand the mechanism behind the ability ofthe anti-VCAM-1 coaguligand to bind to the VCAM-1 constitutivelyexpressed on blood vessels in the heart and lungs, and yet not to causethrombosis in those vessels. There are numerous scientific possibilitiesfor this empirical observation, generally connected with theprothrombotic nature of the tumor environment and any fibrinolyticpredisposition in the heart and lungs.

Generally, there is a biological equilibrium between the coagulationsystem (fibrin deposition) and the fibrinolytic system (degradation offibrin by enzymes). However, in malignant disease, particularlycarcinomas, this equilibrium is disrupted, resulting in the abnormalactivation of coagulation (hypercoagulability or the “prothromboticstate”). Despite extensive research, a clear molecular explanation forthe prothrombotic nature of the tumor environment could not be discerneduntil recently.

After detailed analyses of many possible options, the inventors reasonedthat the failure of the anti-VCAM-1 coaguligand to cause thrombosis invessels of normal tissues was due to the absence of theaminophospholipid, phosphatidylserine (PS) from the luminal surface ofsuch vessels. To complete the theory, therefore, not only wouldphosphatidylserine have to be shown to be absent from these normalvessels, but its presence on the luminal side of tumor-associatedvessels would have to be demonstrated.

The inventors therefore used immunohistochemical staining to evaluatethe distribution of a monoclonal anti-phosphatidylserine (anti-PS)antibody injected intravenously into tumor-bearing mice. These studiesrevealed that the VCAM-1 expressing vessels in the heart and lungslacked PS, whereas the VCAM-1 expressing vessels in the tumor expressedPS. The need for surface PS expression in coaguligand action is furtherindicated by the inventors' finding that annexin V, which binds to PS,blocks anti-VCAM-1·tTF coaguligand action, both in vitro and in vivo.

The lack of thrombotic effect of the anti-VCAM-1 coaguligand on normalheart and lung vessels was thus explained, at least in part: the absenceof the aminophospholipid, phosphatidylserine, means that the normalvessels lack a procoagulant surface upon which coagulation complexes canassemble. In the absence of surface PS, anti-VCAM-1·tTF binds to VCAM-1expressing heart and lung vessels, but cannot induce thrombosis. Incontrast, VCAM-1 expressing vessels in the tumor show coincidentexpression of surface PS. The coaguligand thus binds to tumor vesselsand activates coagulation factors locally to form an occlusive thrombus.

In addition to delineating the tumor-specific thrombotic effects ofanti-VCAM-1 coaguligands, the specific expression of theaminophospholipid, phosphatidylserine, on the luminal surface of tumorblood vessels also allowed the inventors to explain the prothromboticphenotype observed, but not understood, in earlier studies. The PSexpression plays a significant role in the prothrombotic state of tumorvasculature.

Following their discovery that the representative aminophospholipid,phosphatidylserine, was specifically expressed on the luminal surface oftumor blood vessels, but not in normal blood vessels, the inventorsreasoned that other aminophospholipids had potential as targets fortherapeutic intervention. The inventors therefore developed tumorvasculature targeting and treatment methods based on targeting theaminophospholipids phosphatidylserine and phosphatidylethanolamine (PE).

A particularly surprising aspect of the inventors' studies was thatadministration of an unconjugated anti-aminophospholipid antibody waseffective in tumor treatment. This gave rise to important new avenues oftumor treatment using unconjugated or “naked” antibodies that bind toaminophospholipids. These tumor vasculature targeting and treatmentmethods are described in U.S. Pat. No. 6,406,693, incorporated herein byreference. Although anti-tumor effects in art-accepted animal models aredemonstrated in U.S. Pat. No. 6,406,693, and extended herein, theability of aminophospholipids to act as safe and effective targetablemarkers of tumor vasculature could not have been predicted from studiesprevious to U.S. Pat. No. 6,406,693.

Once the discovery of aminophospholipids as specific markers of tumorvasculature had been proven, the inventors began to develop a range ofaminophospholipid-targeted immunotoxins and coaguligands for use intumor treatment. As explained in U.S. Pat. No. 6,406,693, this led tothe unexpected discovery of naked anti-aminophospholipid antibodies foruse in tumor treatment. In investigating the potential ofaminophospholipid targeting in the context of delivering a toxin orcoagulant to the tumor vasculature, the inventors serendipitously foundthat naked anti-PS antibodies had a destructive effect on tumorvasculature in vivo in the absence of any additional effector moiety.The ability of anti-aminophospholipid antibodies to both specificallylocalize to tumor vasculature and to exert a concomitant destructiveeffect, leading to tumor necrosis, was most unexpected.

The present invention provides surprising and improved, “secondgeneration” anti-PS antibodies for use, amongst other embodiments, asnaked antibodies in tumor treatment. A panel of second generationanti-PS antibodies is disclosed herein, of which the monoclonalantibodies 9D2 and 3G4 (ATCC 4545) are currently preferred, along withparticular immunization and screening techniques for the generation andselection of further antibodies with such advantageous properties. It isalso shown herein that vascular damage to tumor vessels by anti-PSantibodies is mediated, at least in part, through host effectors. Theseand other insights of the present inventors allow for naked antibodytreatment to be optimized, both when used alone, and in combination withother anti-cancer agents, as taught herein.

B. Tumor Treatment Using Antibodies to Anionic Phospholipids

U.S. Pat. No. 6,406,693 explains that the aminophospholipidsphosphatidylserine and phosphatidylethanolamine are normally segregatedto the inner surface of the plasma membrane bilayer in different cells(Gaffet et al., 1995; Julien et al., 1995) and that this lipidsegregation creates an asymmetric transbilayer. Although the existenceof membrane asymmetry has been discussed for some time, the reason forits existence and the mechanisms for its generation and control arepoorly understood (Williamson and Schlegel, 1994), particularly in cellsother than platelets.

The inventors earlier demonstrated that PS is translocated to thesurface of tumor vascular endothelial cells and that this occurs, atleast in significant part, independently of apoptotic or othercell-death mechanisms (U.S. Pat. No. 6,406,693). Thus, PS surfaceexpression in the tumor environment is not a consequence of cell death,nor does it trigger immediate cell destruction. Despite PS exposurebeing detected consistently on intact vascular endothelial cells invarious solid tumors, the tumor vascular endothelium is not franklyapoptotic, but is morphologically sound (although different to that innormal tissues) and metabolically active. This is important fortherapeutic methods based on PS targeting, meaning that PS translocationto the outer membrane in tumor vascular endothelial cells issufficiently stable for PS to serve as a targetable entity forsuccessful therapy (using either naked antibodies or therapeuticconjugates).

Despite the important discoveries of U.S. Pat. Nos. 6,406,693 (and6,312,694, see below), the suggestions for phospholipid-based targetingof tumor vascular endothelial cells were confined to the targeting ofaminophospholipids, such as PS and PE. Through the development ofbiological tools with exquisite specificity for different phospholipidsand aminophospholipids, the present inventors have now identified a newcategory of phospholipids that are surprisingly upregulated on tumorvascular endothelial cells. These are the anionic phospholipids, whichare shown herein to also be specific and stable markers of tumorvasculature, permitting therapeutic intervention using both nakedantibodies and immunoconjugates that bind to anionic phospholipids.

Anionic phospholipids are largely absent from the surface of restingmammalian cells under normal conditions. Phosphatidylserine, which isthe most abundant anionic phospholipid of the plasma membrane, istightly segregated to the internal leaflet of the plasma membrane inmost cell types under normal conditions (Williamson and Schlegel, 1994;Zwaal and Schroit, 1997). Phosphatidylinositol (PI), another majoranionic phospholipid, is also predominantly situated in the internalleaflet of the plasma membrane (Calderon and DeVries, 1997). The minoranionic phospholipids, phosphatidic acid (PA) and phosphatidylglycerol(PG), have only been examined in a few cells types, but they also appearto be mainly situated in the internal leaflet of the plasma membrane(Hinkovska-Galcheva et al., 1989). Cardiolipin (CL), another anionicphospholipid, is present in the mitochondrial membrane and is absentfrom the plasma membrane (Daum, 1985).

The neutral phospholipids are also asymmetrically distributed in theplasma membrane. The neutral aminophospholipid, phosphatidylethanolamine(PE) is predominately on the internal leaflet. The choline-containingneutral phospholipids, phosphatidylcholine (PC) and sphingomyelin (SM),are predominantly on the external leaflet.

PS asymmetry, along with that of PE, is maintained by an ATP-dependenttransporter, aminophospholipid translocase (Mg²⁺ ATPase), whichcatalyzes the transport of aminophospholipids from the external leafletto the internal leaflet of the plasma membrane (Seigneuret and Devaux,1984). Loss or collapse of PS and PE asymmetry results from the outwardmovement of these phospholipids in the plasma membrane and is causedeither by inhibition of the translocase (Bitbol et al., 1987; Comfuriuset al., 1990), activation of PS transporters and/or activation ofscramblase enzymes, Ca²⁺ dependent enzymes that transport all lipidsbidirectionally (Zhao et al., 1998).

Loss of PS asymmetry is observed under different pathological andphysiological conditions, including cell injury, programmed cell deathand apoptosis (Blankenberg et al., 1998; Bombeli et al., 1997), cellaging (Herrmann and Devaux, 1990), activation of platelets (Rote et al.,1993; Zwaal et al., 1989), injury (Boyle et al., 1996) and malignanttransformation (Sugimura et al., 1994). Exposure of PS also plays a rolein intercellular fusion of myoblasts (Sessions and Horwitz, 1981) andtrophoblasts (Adler et al., 1995), cell migration (Vogt et al., 1996)and cell degranulation (Demo et al., 1999). Endothelial cellsexternalize PS in response to increased Ca²⁺ fluxes induced by thrombin(Qu et al., 1996), calcium ionophore or phorbol esters (Julien et al.,1997), hyperlipidemia (Lupu et al., 1993), and non-lytic concentrationsof complement proteins C5b-9 (Christiansen et al., 1997). Spontaneous PSexposure has been also observed in malignant cells in the absence ofexogenous activators or cell injury (Utsugi et al., 1991).

Several major consequences follow membrane PS exposure. Phagocyticmacrophages recognize, attach and eliminate PS-positive senescent andapoptotic cells (McEvoy et al., 1986; Tait and Smith, 1999). PS alsomediates attachment of T lymphocytes to thrombin-activated endothelialcells (Qu et al., 1996). The complement system is activated by PS andcontributes to the lysis of PS-positive cells (Test and Mitsuyoshi,1997). Finally, PS exposure contributes to a procoagulant shift on theendothelium (Williamson and Schlegel, 1994; Bombeli et al., 1997) byproviding a negatively charged lipid surface for assembly and activationof coagulation complexes (Bevers et al., 1985; Dachary-Prigent et al.,1996). The prothrombotic character of the tumor endothelium has longbeen recognized (Donati and Falanga, 2001).

Despite the focus on PS in the scientific literature, and the inventors'earlier work confined to aminophospholipids such as PS and PE (U.S. Pat.Nos. 6,406,693 and 6,312,694), the present inventors hypothesized that awider category of phospholipids could become exposed on tumorvasculature. Due to the increased stress conditions of the tumormicroenvironment, the inventors reasoned that a range of anionicphospholipids could be upregulated on tumor vasculature, providingpotential new opportunities for therapeutic intervention.

The inventors realized that injury and activation of tumor endotheliumare caused by: 1) tumor-derived cytokines, such as interleukin-1 andtumor necrosis factor, which activate the endothelium and induceexpression of cell adhesion molecules (Shaughnessy et al., 1989; Orr etal., 2000); 2) reactive oxygen species (ROS) generated by leukocytesthat adhere to the endothelium (Orr et al., 2000); and 3) ROS generatedby tumor cells themselves as a byproduct of metabolism (Shaughnessy etal., 1989; Soares et al., 1994) or as a result of exposure to hypoxiafollowed by reoxygenation (Zulueta et al., 1995). These observationssuggested that Ca²⁺ fluxes might be generated by these stresses withinthe tumor endothelium that, in turn, cause exposure of PS and PE,through activation of scramblase or inhibition of aminophospholipidtranslocase.

However, the inventors extended these insights to the hypothesis thatanionic phospholipids, not just the aminophospholipids PS and PE, wouldbe upregulated on tumor vasculature. To detect cell surface anionicphospholipids, the inventors generated a new monoclonal antibody, 9D2,which reacts with anionic but not neutral phospholipids. 9D2 thusdifferentiates from general aminophospholipid binding agents, as itbinds to the anionic aminophospholipid, PS, but not to the neutralaminophospholipid, PE. The 9D2 antibody is also more specific foranionic phospholipids than is the natural ligand, annexin V, whichstrongly binds to PE, in addition to anionic phospholipids (Blankenberget al., 1998).

As detailed in the present application, the inventors found that 9D2 andannexin V localize specifically to tumor endothelium after intravenousinjection to mice bearing various types of solid tumors. This findingvalidates the inventors' hypothesis that anionic phospholipids routinelybecome exposed on the surface of tumor vascular endothelium and can beused as target molecules for tumor therapy (and imaging). The presentinvention thus provides a range of new methods and antibody-basedcompositions for use in targeting anionic phospholipids and treatingtumors, both in terms of naked antibodies and in the delivery ofcytotoxic drugs, cytokines, coagulants and such like. In addition totargeting PS, as taught in U.S. Pat. Nos. 6,406,693 and 6,312,694, thecurrently preferred anionic phospholipids for targeting by the presentinvention are PI, a major anionic phospholipid, PA and PG, withtargeting CL also being contemplated in certain embodiments.

One of the major findings to emerge from the present invention is thatanionic phospholipids are exposed on the surface of tumor endothelium(Example VI). This phenomenon was demonstrated using two independentreagents that bind selectively to anionic phospholipids: a monoclonalantibody, 9D2, developed by the inventors particularly to validate thispoint, and annexin V. The 9D2 antibody and competing antibodies arefurther preferred components of the present invention.

9D2 antibody and annexin V bind with high affinity and specificity toanionic phospholipids adsorbed to plastic, as liposomes, or presented onthe membrane surface of activated or apoptotic endothelial cells invitro. 9D2 binds strongly to PS, PA and CL, but more weakly to PI andPG. Annexin V binds to PE in addition to PS, CL, PA, PI and PG, as foundpreviously (Andree et al., 1990; Schlaepfer et al., 1987; Boustead etal., 1993; Blackwood and Ernst, 1990). Recognition of anionicphospholipids by 9D2 antibody was identical in the presence and absenceof serum, indicating that binding does not require serum co-factors.Binding of 9D2 to anionic phospholipids, did not require Ca²⁺ ions,whereas the binding of annexin V did require Ca²⁺.

Cross-blocking studies on PS-coated plates showed that 9D2 and annexin Vdo not block each other's binding to PS. This indicates that the tworeagents recognize different epitopes on the PS molecule, or, morelikely, differently packed forms of PS. Annexin V is thought to bind toplanar PS surfaces, whereas anti-PS antibodies are thought to bind tohexagonally packed PS (Rauch and Janoff, 1990). Both forms are probablypresent on PS-coated plates. These practical cross-blocking studies(Example VI) also serve to show that antibodies which effectivelycompete for binding to anionic phospholipids, i.e., bind to essentiallythe same epitope, can be readily identified once a reference antibody(e.g. 9D2) is provided.

The present application also shows that 9D2 antibody and annexin Vspecifically localize to tumor vessels, and to tumor cells in and aroundnecrotic regions of all tumors examined in vivo (Example VI). Between 15and 40% of blood vessels in the tumors had anionic phospholipid-positiveendothelium. In contrast, none of the blood vessels in normal tissueshad detectable externalized anionic phospholipids.

The specificity of staining of tumor vasculature by 9D2 was demonstratedby: 1) the lack of tumor vessel staining by control rat IgM; 2) theblocking of 9D2 or annexin V binding to H₂O₂-treated endothelial cellsin vitro by liposomes prepared from anionic phospholipids, but notneutral phospholipids; 3) the finding that extraction of phospholipidsfrom tumor sections with detergents or organic solvents abolishedstaining; and 4) the lack of localization of either 9D2 or annexin V tothe quiescent endothelium in normal organs.

The main anionic phospholipid that is localized by 9D2 or annexin V ontumor vasculature is likely to be PS, as this is the most abundantanionic phospholipid and its exposure on the cell surface is regulatedby environmental influences or injury. However, other anionicphospholipids (e.g., PI, PA, PG) are also likely to be exposed, despitebeing less abundant.

Although not detected by 9D2, the major neutral phospholipid, PE, islikely to contribute, together with PS, to the annexin localizationobserved on tumor vessels. PE is also known to be exposed on tumorendothelium, and the position of PE in the plasma membrane is regulatedin a similar manner to PS (U.S. Pat. No. 6,406,693). PE is segregated tothe internal leaflet of the plasma membrane in part by aminophospholipidtranslocase, although at a slower rate than PS (Devaux, 1992), and istransported to the external surface by scramblase (Zhou et al., 1997).PE, like PS, is also exposed during apoptosis and cell activation (Emotoet al., 1997; Umeda and Emoto, 1999).

To examine the mechanism of exposure of anionic phospholipids on tumorendothelial cells, a series of studies was performed in whichendothelial cells in vitro were treated with various factors andconditions known to be present in the tumor microenvironment (ExampleVII). Hypoxia followed by re-oxygenation, acidity, and thrombinincreased PS exposure on viable endothelial cells to between 10 and 22%of the level seen when all cells are apoptotic. Inflammatory cytokines(TNFα and IL-1) also caused a weak but definite induction of PSexposure.

These findings are consistent with the possibility that, in tumors,exposure of anionic phospholipids on the vascular endothelium is inducedby hypoxia/reoxygenation in combination with inflammatory cytokines,thrombin and acidity. Although the precise mechanism does not need to beunderstood to practice the present invention, ROS may be generated bytumor cells as a bi-product of metabolism or in response to hypoxia(Zulueta et al., 1995). Cytokines released by tumor cells may induceleukocytes adhesion molecules on the endothelium that mediate adherenceof activated macrophages, polymorphonuclear cells and platelets to tumorendothelium and further secretion of ROS. The ROS may then induce PStranslocation through oxidation of thiol-containing transport moleculesor peroxidation of lipids (Herrmann and Devaux, 1990), possibly bycausing an influx of Ca²⁺ or release of Ca²⁺ from intracellular stores(Wang and Joseph, 2000).

Exposure of PS and other anionic phospholipids in part explains theprocoagulant status of tumor endothelium that has long been recognized(Donati and Falanga, 2001). The anionic phospholipids provide thesurface upon which coagulation factors concentrate and assemble (Beverset al., 1985; Dachary-Prigent et al., 1996). It also provides anattachment site for circulating macrophages (McEvoy et al., 1986), Tlymphocytes (Qu et al., 1996) and polymorphonuclear cells that assistsin leukocyte infiltration into tumors.

Antibodies and other ligands that bind to anionic phospholipids can thusbe used for the targeting, imaging and/or treatment of tumor bloodvessels. Anionic phospholipids are attractive as tumor target vesselsfor several reasons: they are abundant (PS is present at 3×10⁶ moleculesper cell); they are on the luminal surface of tumor endothelium, whichis directly accessible for binding by vascular targeting agents in theblood; they are present on a major percentage of tumor endothelial cellsin diverse solid tumors; and they are essentially absent fromendothelium in all normal tissues.

Vascular targeting agents employing drugs or coagulants have been shownto be highly effective, and sometimes curative, in mice with large solidtumors (Huang et al., 1997; Nilsson et al., 2001; U.S. Pat. Nos.5,660,827, 5,776,427, 5,855,866, 5,863,538, 5,965,132, 6,004,554,6,051,230, 6,261,535, 6,093,399, 6,004,555, 5,877,289 and 6,036,955).The present invention thus provides naked antibodies and vasculartargeting agents directed against anionic phospholipids for use intargeting tumor vasculature in the diagnosis and treatment of cancer inman.

Although a precise molecular understanding of how naked antibodiesdirected against anionic phospholipids and aminophospholipids functionin tumor treatment is not necessary in order to practice the treatment,the inventors have contemplated several mechanisms that may account forthe observed endothelial cell killing. The favored mechanisms(particularly for the 3G4 antibody described herein) are Fcdomain-mediated immune effector functions, such as antibody-dependentcellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC)and antibody mediated phagocytosis. Cell-mediated cytotoxicity,complement-mediated lysis and/or apoptosis, antibody-induced cellsignaling and/or disturbances to the cytoskeleton may also be involved.

Binding of intact antibodies against anionic phospholipids andaminophospholipids, particularly 3G4, to the vascular endothelial cellsurface means that the Fc portions of the antibodies protrude into thevessel lumen. As antibody Fc fragments activate the complement pathway,the observed cellular destruction may be a result of complement-directedlysis. Antibody binding thus activates the complement-dependentcoagulation cascade, causing multi-component complexes to assemble and,ultimately, to generate a lytic complex that permeabilizes the targetcell. “Complement-activated ADCC” may also be operating in thedestruction, in which complement binds to the antibody-coated targetcell, and in which cells, such as neutrophils, having receptors forcomplement, lyse the target cell.

As the naked or unconjugated antibodies, including the antigen bindingfragments thereof, bind to anionic phospholipids and aminophospholipidsat the surface of the tumor vascular endothelial cells, they will forman antibody coating on the luminal surface. This may function to attractimmune effector cells, such as cytotoxic T cells and/or natural killer(NK) cells, which will then exert a cell-mediated cytotoxic effect onthe vascular endothelial cells.

Antibody binding to anionic phospholipids and aminophospholipids mayalso induce apoptosis in the tumor vascular endothelial cells. Althoughthere are no known reports of antibody binding to PS actually inducingapoptosis (rather than PS being a marker resulting from apoptosis), theinventors consider this to be another possible mechanism for theobserved anti-tumor effects.

It is also possible that antibody binding to anionic phospholipids andaminophospholipids at the surface of tumor vascular endothelial cellsmay cause disturbances in the cytoskeletalal organization of the cell.As the cytoskeleton plays a role in the organization of surfacemembranes, and as antibody binding may disturb (or further disturb) themembrane, binding of antibodies to anionic phospholipids andaminophospholipids may transmit changes to cytoskeletal proteins thatinteract with the bilayer. It is already known that the spatialorganization of cytoskeletal proteins controls membrane stability andcell shape, and it is possible that perturbation of some cytoskeletalequilibrium may have far-reaching consequences on cell integrity.

A further mechanism of operation of the invention may be that antibodybinding to anionic phospholipids and aminophospholipids at theendothelial cell surface may initiate signal transduction by, as yet,undefined pathways. Antibody binding may also disturb known signaltransduction pathways, e.g., by altering the conformation and/orinteractions of membrane receptors, signal transduction proteins,membrane channels, and the like. Signals for cell destruction(apoptosis) may be initiated or mimicked, and/orpreservation/homeostatic signals may be inhibited.

Although of scientific interest, determining the exact nature of thevascular destruction achieved by the naked antibodies to anionicphospholipids and aminophospholipids is not necessary to practice thetreatment. Given that the administration of these categories ofantibodies is shown to advantageously result in specific anti-tumoreffects in vivo, the treatment can be utilized irrespective of themolecular mechanism that underlies this phenomenon. The use of nakedantibodies that bind to anionic phospholipids and aminophospholipids,thus represents an important advance in tumor therapy, providingadvantages in preparation and cost.

C. Antibodies to Anionic Phospholipids and Aminophospholipids

As the present invention identifies a new category of tumor vasculaturemarkers, the anionic phospholipids, naked antibodies andimmunoconjugates that bind to one or more anionic phospholipids,optionally in combination with aminophospholipids, can now be used intumor diagnosis and treatment.

C1. Polyclonal Antibodies

Means for preparing and characterizing antibodies are well known in theart (see, e.g., Antibodies: A Laboratory Manual, Cold Spring HarborLaboratory, 1988; incorporated herein by reference). To preparepolyclonal antisera an animal is immunized with a composition comprisingan immunogenic anionic phospholipid and/or aminophospholipid, includingcells treated with H₂O₂ and other agents, as taught herein, and antiseracollected from that immunized animal. A wide range of animal species canbe used for the production of antisera. Typically the animal used forproduction of anti-antisera is a rabbit, mouse, rat, hamster, guinea pigor goat. Because of the relatively large blood volume of rabbits, arabbit is a preferred choice for production of polyclonal antibodies.

The amount of immunogen composition used in the production of polyclonalantibodies varies upon the nature of the immunogen as well as the animalused for immunization. A variety of routes can be used to administer theimmunogen; subcutaneous, intramuscular, intradermal, intravenous,intraperitoneal and intrasplenic. The production of polyclonalantibodies may be monitored by sampling blood of the immunized animal atvarious points following immunization. A second, booster injection, mayalso be given. The process of boosting and titering is repeated until asuitable titer is achieved. When a desired titer level is obtained, theimmunized animal can be bled and the serum isolated and stored. Theanimal can also be used to generate monoclonal antibodies.

As is well known in the art, the immunogenicity of a particularcomposition can be enhanced by the use of non-specific stimulators ofthe immune response, known as adjuvants. Exemplary adjuvants includecomplete Freund's adjuvant, a non-specific stimulator of the immuneresponse containing killed Mycobacterium tuberculosis; incompleteFreund's adjuvant; and aluminum hydroxide adjuvant.

It may also be desired to boost the host immune system, as may beachieved by associating anionic phospholipids and aminophospholipidswith, or coupling to, a carrier. Exemplary carriers are keyhole limpethemocyanin (KLH) and bovine serum albumin (BSA). Other albumins such asovalbumin, mouse serum albumin or rabbit serum albumin can also be usedas carriers.

As is also known in the art, a given composition may vary in itsimmunogenicity. However, the generation of antibodies against anionicphospholipids and aminophospholipids is not particularly difficult. Forexample, highly specific anti-phosphatidylserine antibodies were raisedin rabbits immunized by intramuscular injections ofphosphatidylserine-containing polyacrylamide gels and withphosphatidylserine-cytochrome c vesicles (Maneta-Peyret et al., 1988;1989; each incorporated herein by reference). The use of acrylamideimplants enhanced the production of antibodies (Maneta-Peyret et al.,1988; 1989). The anti-phosphatidylserine antibodies raised in thismanner are able to detect phosphatidylserine in situ on human platelets(Maneta-Peyret et al., 1988). The groups of Inoue, Rote and Rauch havealso developed anti-PS and anti-PE antibodies (see below).

Although the generation of antibodies against anionic phospholipids andaminophospholipids can be achieved by various means, certain preferredmethods are described herein in Example IV.

C2. Monoclonal Antibodies

Various methods for generating monoclonal antibodies (MAbs) are also nowvery well known in the art. The most standard monoclonal antibodygeneration techniques generally begin along the same lines as those forpreparing polyclonal antibodies (Antibodies: A Laboratory Manual, ColdSpring Harbor Laboratory, 1988; incorporated herein by reference). Apolyclonal antibody response is initiated by immunizing an animal withan immunogenic anionic phospholipid and/or aminophospholipid compositionand, when a desired titer level is obtained, the immunized animal can beused to generate MAbs. Preferably, the particular screening andselection techniques disclosed herein are used to select antibodies withthe sought after properties.

MAbs may be readily prepared through use of well-known techniques, suchas those exemplified in U.S. Pat. No. 4,196,265, incorporated herein byreference. Typically, this technique involves immunizing a suitableanimal with the selected immunogen composition. The immunizingcomposition is administered in a manner effective to stimulate antibodyproducing cells. Rodents such as mice and rats are preferred animals,however, the use of rabbit, sheep and frog cells is also possible. Theuse of rats may provide certain advantages (Goding, 1986, pp. 60-61;incorporated herein by reference), but mice are preferred, with theBALB/c mouse being most preferred as this is most routinely used andgenerally gives a higher percentage of stable fusions.

Following immunization, somatic cells with the potential for producingthe desired antibodies, specifically B lymphocytes (B cells), areselected for use in the MAb generating protocol. These cells may beobtained from biopsied spleens, tonsils or lymph nodes, or from aperipheral blood sample. Spleen cells and peripheral blood cells arepreferred, the former because they are a rich source ofantibody-producing cells that are in the dividing plasmablast stage, andthe latter because peripheral blood is easily accessible. Often, a panelof animals will have been immunized and the spleen of animal with thehighest antibody titer will be removed and the spleen lymphocytesobtained by homogenizing the spleen with a syringe. Typically, a spleenfrom an immunized mouse contains approximately 5×10⁷ to 2×10⁸lymphocytes.

The antibody-producing B lymphocytes from the immunized animal are thenfused with cells of an immortal myeloma cell, generally one of the samespecies as the animal that was immunized. Myeloma cell lines suited foruse in hybridoma-producing fusion procedures preferably arenon-antibody-producing, have high fusion efficiency, and enzymedeficiencies that render then incapable of growing in certain selectivemedia which support the growth of only the desired fused cells(hybridomas).

Any one of a number of myeloma cells may be used, as are known to thoseof skill in the art (Goding, pp. 65-66, 1986; Campbell, pp. 75-83, 1984;each incorporated herein by reference). For example, where the immunizedanimal is a mouse, one may use P3-X63/Ag8, X63-Ag8.653, NS1/1.Ag 4 1,Sp210-Ag14, FO, NSO/U, MPC-11, MPC11-X45-GTG 1.7 and S194/5XX0 Bul; forrats, one may use R210.RCY3, Y3-Ag 1.2.3, IR983F, 4B210 or one of theabove listed mouse cell lines; and U-266, GM 1500-GRG2, LICR-LON-HMy2and UC729-6, are all useful in connection with human cell fusions.

Methods for generating hybrids of antibody-producing spleen or lymphnode cells and myeloma cells usually comprise mixing somatic cells withmyeloma cells in a 4:1 proportion, though the proportion may vary fromabout 20:1 to about 1:1, respectively, in the presence of an agent oragents (chemical or electrical) that promote the fusion of cellmembranes. Fusion methods using Sendai virus have been described byKohler and Milstein (1975; 1976; each incorporated herein by reference),and those using polyethylene glycol (PEG), such as 37% (v/v) PEG, byGefter et al. (1977; incorporated herein by reference). The use ofelectrically induced fusion methods is also appropriate (Goding pp.71-74, 1986; incorporated herein by reference).

Fusion procedures usually produce viable hybrids at low frequencies,about 1×10⁻⁶ to 1×10⁻⁸. However, this does not pose a problem, as theviable, fused hybrids are differentiated from the parental, unfusedcells (particularly the unfused myeloma cells that would normallycontinue to divide indefinitely) by culturing in a selective medium. Theselective medium is generally one that contains an agent that blocks thede novo synthesis of nucleotides in the tissue culture media. Exemplaryand preferred agents are aminopterin, methotrexate, and azaserine.Aminopterin and methotrexate block de novo synthesis of both purines andpyrimidines, whereas azaserine blocks only purine synthesis. Whereaminopterin or methotrexate is used, the media is supplemented withhypoxanthine and thymidine as a source of nucleotides (HAT medium).Where azaserine is used, the media is supplemented with hypoxanthine.

The preferred selection medium is HAT. Only cells capable of operatingnucleotide salvage pathways are able to survive in HAT medium. Themyeloma cells are defective in key enzymes of the salvage pathway, e.g.,hypoxanthine phosphoribosyl transferase (HPRT), and they cannot survive.The B cells can operate this pathway, but they have a limited life spanin culture and generally die within about two weeks. Therefore, the onlycells that can survive in the selective media are those hybrids formedfrom myeloma and B cells.

This culturing provides a population of hybridomas from which specifichybridomas are selected. Typically, selection of hybridomas is performedby culturing the cells by single-clone dilution in microtiter plates,followed by testing the individual clonal supernatants (after about twoto three weeks) for the desired reactivity. The assay should besensitive, simple and rapid, such as radioimmunoassays, enzymeimmunoassays, cytotoxicity assays, plaque assays, dot immunobindingassays, and the like.

The selected hybridomas would then be serially diluted and cloned intoindividual antibody-producing cell lines, which clones can then bepropagated indefinitely to provide MAbs. The cell lines may be exploitedfor MAb production in two basic ways. A sample of the hybridoma can beinjected (often into the peritoneal cavity) into a histocompatibleanimal of the type that was used to provide the somatic and myelomacells for the original fusion. The injected animal develops tumorssecreting the specific monoclonal antibody produced by the fused cellhybrid. The body fluids of the animal, such as serum or ascites fluid,can then be tapped to provide MAbs in high concentration. The individualcell lines could also be cultured in vitro, where the MAbs are naturallysecreted into the culture medium from which they can be readily obtainedin high concentrations.

MAbs produced by either means will generally be further purified, e.g.,using filtration, centrifugation and various chromatographic methods,such as HPLC or affinity chromatography, all of which purificationtechniques are well known to those of skill in the art. Thesepurification techniques each involve fractionation to separate thedesired antibody from other components of a mixture. Analytical methodsparticularly suited to the preparation of antibodies include, forexample, protein A-Sepharose and/or protein G-Sepharose chromatography.

D. Second Generation Antibodies to Anionic Phospholipids andAminophospholipids

The present invention provides “second generation” antibodies that bindto aminophospholipids and anionic phospholipids, which antibodies haveimproved properties and/or do not suffer from the drawback associatedwith the antibodies in the prior art. A panel of such antibodies isdisclosed herein, of which the monoclonal antibodies 9D2 and 3G4 arecurrently preferred, with the 3G4 (ATCC 4545) antibody beingparticularly preferred. The invention also provides particularimmunization and screening techniques, which permit “like” or“competing” antibodies with advantageous properties and/or lessdrawbacks to be produced.

D1. Antibody Properties

The second generation antibodies of the invention bind toaminophospholipids and anionic phospholipids and yet do not havepathogenic properties usually associated with antibodies to suchphospholipids. This was made possible, in part, by the new immunizationand screening techniques developed by the inventors.

Anti-phospholipid syndrome(s) (APS) are associated with autoantibodiestermed “anti-cardiolipin” antibodies and “lupus anticoagulantantibodies”. These syndromes are associated with a predispositiontowards venous and arterial thromboemboli, thrombocytopenia and a numberof neurological syndromes. The anti-phospholipid antibodies in thesepatients are thus “pathogenic antibodies”.

Although described for years as “anti-phospholipid antibodies” and“anti-PS antibodies”, such pathogenic antibodies in fact recognizeprotein cofactors that bind to cardiolipin, PS or both, not thephospholipids themselves (Galli et al., 1990; 1993; McNeil et al., 1990;Rote, 1996). Anti-cardiolipin antibodies recognize a particular region(between residue 281 and residue 288) on β2-glycoprotein I, whereaslupus anticoagulant antibodies recognize prothrombin. Similarly, anti-PEantibodies that occur in disease states bind to PE in combination withproteins, such as low and high molecular weight kininogen (HK),prekallikrein and factor XI (Sugi and McIntyre, 1995; 1996a; 1996b).Based upon this type of protein recognition, the anti-phospholipidantibodies in patients displace the protein cofactors from thephospholipids, thus creating the symptoms of disease.

Certain of the antibodies of the present invention have beenparticularly selected on the basis of not binding to aminophospholipidsand anionic phospholipids in combination with protein cofactors, butrather are “true” anti-phospholipid antibodies. Certain of theantibodies of the invention do not bind or displace the proteincofactors from the phospholipids and are therefore safe foradministration. Indeed, mice treated with the antibodies of theinvention at high doses for prolonged periods showed no changes incoagulation capability, yet mice respond with APS when injected withanticardiolipin or lupus anticoagulant antibodies.

Irrespective of the underlying mechanisms, anti-phospholipid antibodiesoccurring in the human population are correlated with autoimmunediseases, e.g., systemic lupus erythematosus (Branch et al., 1987; Staubet al., 1989; Drouvalakis and Buchanan, 1998; Smirnov et al., 1995;Rauch et al., 1986; Rauch and Janoff, 1990) and recurrent pregnancy loss(Rote et al., 1995; Rote, 1996; Vogt et al., 1996; 1997; Katsuragawa etal., 1997). No such symptoms have been associated when the antibodies ofthe present invention are administered to mice or monkeys.

Also, the epitope recognized by the antibodies of the invention, such asthe 9D2 and 3G4 (ATCC 4545) antibodies, is not the same as thatrecognized by annexin V. This is shown herein, as the agents do notcrossblock each others' binding to phospholipids. The epitope recognizedby the 3G4 and 9D2 antibodies is probably a hexagonally packed form ofPS, which is the immunogenic form. Annexin V likely binds to planar PSin addition to the hexagonal form. The hexagonal form of PS concentratesinto protuberances in the plasma membrane associated with cellactivation and into “blebs” on apoptotic cells. The restricteddistribution of the antibodies of the invention, such as the 9D2 and 3G4(ATCC 4545) antibodies, thus further contributes to the lack ofdetectable toxicity and lack of effect on coagulation of the antibodies.

In order to generate antibodies to aminophospholipids and anionicphospholipids with advantageous properties and/or reduced or essentiallyno side effects, the present invention provides preferred immunizationand screening methods. Other immunization techniques and antibodies havebeen reported in the literature (Umeda et al., 1989; Igarashi et al.,1991; Rote et al., 1993), including those with reported specificity forthe type of fatty acid chains involved (Levy et al., 1990; Qamar et al.,1990). However, the present immunization techniques, and particularlythe selection of antibodies that are not serum dependent, providesparticular benefits.

Umeda et al. (1989) reported the production of monoclonal antibodiesrecognizing stereo-specific epitopes of phosphatidylserine. However, theUmeda system suffers from the drawback of using direct immunization ofphosphatidylserine into mouse spleen using a Salmonella-coatedaminophospholipid sample (Umeda et al., 1989). Many of the antibodiesreported by Umeda et al. (1989) also exhibit anticoagulant activity,which is a drawback not associated with the antibodies of the presentinvention. The binding profile of the 3G4 antibody is different to thatof the PSC8 antibody of Umeda et al. (1989).

The antibodies of the invention also have the advantage of recognizingall or most anionic phospholipids, which can provide more targets forbinding. Therefore, the second generation antibodies of the inventioncan be defined as having substantially the same, or the same,phospholipid specificity as the 9D2 or 3G4 (ATCC 4545) antibodies, asdisclosed herein in Table 4.

Igarashi et al. (1991) also reported the induction of anti-PSantibodies, but again used intrasplenic immunization and only a slightincrease of the titer was observed when the antigen was again injectedintravenously. Most of the MAbs from Igarashi et al. (1991)cross-reacted with DNA and many exhibited lupus anticoagulant activity,neither of which drawbacks exist in the antibodies developed by thepresent inventors. The binding profile of the preferred, 3G4 antibody ofthe invention is also different to those of the antibodies in Table 1 ofIgarashi et al. (1991).

Others have reported the lupus anticoagulant activities of murinemonoclonal antibodies that cross react with more than one anionicphospholipid (Alving et al., 1987; Rauch and Janoff, 1990), but thepresent inventors have experienced no difficulty in obtaining antibodiesfree from lupus anticoagulant activity. This represents a distinctadvantage of the methods, antibodies and competing antibodies inaccordance with the present invention.

In addition to avoiding the use of antibodies from patients, such asdescribed in Rauch et al. (1986), Hasegawa et al. (1994), Ravirajan etal. (1995) and Menon et al. (1997), the present application alsodemonstrates the advantageous properties of the antibodies provided bythis invention in side-by-side comparisons with existing antibodies fromthe literature, such as the 3SB antibody described by Rote et al.(1993). Although the 3SB antibody has properties suitable for use invarious of the methods disclosed herein, the antibodies developed by thepresent inventors nonetheless out-perform the 3SB antibody incomparative studies, e.g., as shown herein by the increased anti-viraleffects of the 3G4 antibodies as opposed to the 3SB antibody (ExampleXIII).

The antibodies of the present invention can also be characterized bytheir affinity. Prior to the invention, the antibodies in the literaturehad relatively weak affinity (where reported). In certain embodiments,the second generation antibodies of the invention are therefore definedas those that have an affinity for PS of at least equal to the affinityof the 9D2 or 3G4 (ATCC 4545) antibodies for PS, in particular, theaffinity when measured in an ELISA as described herein, as disclosed inTable 3.

More preferably, the second generation antibodies of the invention aredefined as those having an affinity for PS of at least equal to theaffinity of the 9D2 or 3G4 (ATCC 4545) antibodies for PS, as disclosedin Table 3, and as having substantially the same, or the same,phospholipid specificity as the 9D2 or 3G4 (ATCC 4545) antibodies, asdisclosed in Table 4. Most preferably, the second generation antibodiesare those having an affinity for PS of at least equal to the affinity ofthe 3G4 (ATCC 4545) antibody for PS, as disclosed in Table 3, and ashaving the same phospholipid specificity as the 3G4 (ATCC 4545)antibody, as disclosed in Table 4.

D2. CDR Technologies

Antibodies are comprised of variable and constant regions. The term“variable”, as used herein in reference to antibodies, means thatcertain portions of the variable domains differ extensively in sequenceamong antibodies, and are used in the binding and specificity of eachparticular antibody to its particular antigen. However, the variabilityis not evenly distributed throughout the variable domains of antibodies.It is concentrated in three segments termed “hypervariable regions”,both in the light chain and the heavy chain variable domains (other thancamelized antibodies discussed below).

The more highly conserved portions of variable domains are called theframework region (FR). The variable domains of native heavy and lightchains each comprise four FRs (FR1, FR2, FR3 and FR4, respectively),largely adopting a β-sheet configuration, connected by threehypervariable regions, which form loops connecting, and in some cases,forming part of, the β-sheet structure.

The hypervariable regions in each chain are held together in closeproximity by the FRs and, with the hypervariable regions from the otherchain, contribute to the formation of the antigen-binding site ofantibodies (Kabat et al., 1991, specifically incorporated herein byreference). The constant domains are not involved directly in binding anantibody to an antigen, but exhibit various effector functions, such asparticipation of the antibody in antibody-dependent cellular toxicity.

The term “hypervariable region”, as used herein, refers to the aminoacid residues of an antibody that are responsible for antigen-binding.The hypervariable region comprises amino acid residues from a“complementarity determining region” or “CDR” (i.e. residues 24-34 (L1),50-56 (L2) and 89-97 (L3) in the light chain variable domain and 31-35(H1), 50-56 (H2) and 95-102 (H3) in the heavy chain variable domain;Kabat et al., 1991, specifically incorporated herein by reference)and/or those residues from a “hypervariable loop” (i.e. residues 26-32(L1), 50-52 (L2) and 91-96 (L3) in the light chain variable domain and26-32 (H1), 53-55 (H2) and 96-101 (H3) in the heavy chain variabledomain). “Framework” or “FR” residues are those variable domain residuesother than the hypervariable region residues as herein defined.

The DNA and deduced amino acid sequences of the Vh and Vκ chains of the3G4 antibody (ATCC 4545) are provided herein as SEQ ID NO:1, 2, 3 and 4,respectively. These sequences encompass CDR1-3 of the variable regionsof the heavy and light chains of the antibody. In light of the sequenceand other information provided herein, and the knowledge in the art, arange of 3G4-like and improved antibodies and antigen binding regionscan now be prepared and are thus encompassed by the present invention.

In certain embodiments, the invention provides at least one CDR of theantibody produced by the hybridoma deposited as ATCC 4545. In otherembodiments, the invention provides a CDR, antibody, or antigen bindingregion thereof, which binds to at least a first aminophospholipid oranionic phospholipid, preferably PS, and which comprises at least oneCDR of the antibody produced by the hybridoma deposited as ATCC 4545.

Further aspects of the invention concern at least one CDR that has a CDRamino acid sequence encompassed by the variable region amino acidsequence of SEQ ID NO:2 or SEQ ID NO:4, or a variant or mutagenized formthereof. Other aspects of the invention concern a CDR, antibody, orantigen binding region thereof, which binds to at least a firstaminophospholipid or anionic phospholipid, preferably PS, and whichcomprises at least one CDR with a CDR amino acid sequence encompassed bythe variable region amino acid sequence of SEQ ID NO:2 or SEQ ID NO:4,or a variant or mutagenized form thereof, wherein such a variant ormutagenized form maintains binding to the aminophospholipid or anionicphospholipid, preferably PS. The heavy chain CDR amino acid sequencesencompassed by the variable region amino acid sequence of SEQ ID NO:2are: VH CDR1 of SEQ ID NO:10, VH CDR2 of SEQ ID NO:11 and VH CDR3 of SEQID NO:12. The light chain CDR amino acid sequences encompassed by thevariable region amino acid sequence of SEQ ID NO:4 are: VL CDR1 of SEQID NO:13, VL CDR2 of SEQ ID NO:14 and VL CDR3 of SEQ ID NO:15.

In one particular embodiment, the invention provides an antibody, orantigen binding region thereof, in which the framework regions of the3G4 antibody (ATCC 4545) have been changed from mouse to a human IgG,such as human IgG₁ or other IgG subclass to reduce immunogenicity inhumans. In other embodiments, the sequences of the 3G4 antibody (ATCC4545) are examined for the presence of T-cell epitopes, as is known inthe art. The underlying sequence can then be changed to remove T-cellepitopes, i.e., to “deimmunize” the antibody.

The availability of the DNA and amino acid sequences of the Vh and Vκchains of the 3G4 antibody (SEQ ID NO:1, 2, 3 and 4) means that a rangeof antibodies can now be prepared using CDR technologies. In particular,random mutations are made in the CDRs and the products screened toidentify antibodies with higher affinities and/or higher specificities.Such mutagenesis and selection is routinely practiced in the antibodyarts. It is particularly suitable for use in the present invention,given the advantageous screening techniques disclosed herein.

These techniques are used to generate antibody variants with improvedbiological properties relative to the parent antibody from which theyare prepared, such as the 9D2 and 3G4 (ATCC 4545) antibodies. Suchvariants, or second generation compounds, are typically substitutionalvariants involving one or more substituted hypervariable region residuesof a parent antibody. A convenient way for generating suchsubstitutional variants is affinity maturation using phage display.

In affinity maturation using phage display, several hypervariable regionsites (e.g. 6-7 sites) are mutated to generate all possible aminosubstitutions at each site. The antibody variants thus generated aredisplayed in a monovalent fashion from filamentous phage particles asfusions to the gene III product of M13 packaged within each particle.The phage-displayed variants are then screened for their biologicalactivity (e.g. binding affinity) as herein disclosed. In order toidentify candidate hypervariable region sites for modification, alaninescanning mutagenesis can be performed to identify hypervariable regionresidues contributing significantly to antigen binding.

CDR shuffling and implantation technologies can also be used with theantibodies of the present invention, preferably the 9D2 and 3G4 (ATCC4545) antibodies. CDR shuffling inserts CDR sequences into a specificframework region (Jirholt et al., 1998, specifically incorporated hereinby reference). CDR implantation techniques permit the random combinationof CDR sequences into a single master framework (Soderlind et al., 1999,2000, each specifically incorporated herein by reference). Using suchtechniques, the CDR sequences of the 3G4 (ATCC 4545) antibody, forexample, are mutagenized to create a plurality of different sequences,which are incorporated into a scaffold sequence and the resultantantibody variants screened for desired characteristics, e.g., higheraffinity.

In light of the information in the present disclosure, the antigenbinding fragment of the antibodies, preferably the 9D2 and 3G4 (ATCC4545) antibodies, can also be minimized, giving enhanced stability. Thiscan be achieved by preparing single domain binding proteins based uponimmunoglobulin V_(H) and V_(H)-like domains (Nuttall et al., 2000,specifically incorporated herein by reference).

Alternatively, or in addition, the crystal structure of theantigen-antibody complex can be delineated and analyzed to identifycontact points between the antibody and target aminophospholipid oranionic phospholipid, e.g., PS. Such contact residues and neighboringresidues are candidates for substitution. Once such variants aregenerated, the panel of variants is subjected to screening, as describedherein, and antibodies with analogous but different or even superiorproperties in one or more relevant assays are selected for furtherdevelopment.

D3. Camelized Antibodies

Further examples of antibodies of the invention are “camelized”antibodies. Antibodies from camels and llamas (Camelidae, camelids)include a unique kind of antibody, which is devoid of light chains andthus formed by heavy chains only. These have been termed “camelizedantibodies”. The antigen-binding site of such antibodies is one singledomain, referred to as V_(HH) (VHH).

As the DNA and amino acid sequences of the Vh and Vκ chains of the 3G4(ATCC 4545) antibody are provided herein (SEQ ID NOs:1, 2, 3 and 4),camelized versions of the 3G4 antibody can also be prepared. Mutationsand structural adaptations can be made to reshape a V_(H) of aV_(H)-V_(L) pair into a single-domain VHH with retention of a sufficientvariability (Muyldermans et al., 2001, specifically incorporated hereinby reference). Such V_(HH) constructs are small, robust and efficientrecognition units (Riechmann and Muyldermans, 1999) with potentantigen-binding capacity, which can provide the further advantage ofinteracting with novel epitopes that are inaccessible to conventionalV_(H)-V_(L) pairs. Thus, camelised antibodies are akin to Fv fragments,but can have additional benefits.

U.S. Pat. No. 5,800,988, U.S. Pat. No. 6,005,079, PCT application No. WO94/04678, PCT application No. WO 94/25591, Riechmann and Muyldermans(1999) and Muyldermans et al. (2001) are each specifically incorporatedherein by reference for the purpose of even further describing andenabling the production of camelized antibodies. Accordingly, the CDRfrom the 3G4 antibody can be grafted on the framework of the variabledomain of the heavy chain immunoglobulin of the Camelidae antibody.

D4. CDR Sequences

Further aspects of the invention therefore concern isolated DNA segmentsand recombinant vectors encoding CDR regions of antibody heavy and lightchains, such as 9D2 and 3G4, and preferably 3G4 (ATCC 4545), heavy andlight chains, and the creation and use of recombinant host cells andphage through the application of DNA technology, which express such CDRregions.

The invention thus provides an isolated polynucleotide that contains anucleotide sequence that encodes at least one CDR of the antibodyproduced by the hybridoma deposited as ATCC 4545. The invention furtherprovides an isolated polynucleotide that contains a nucleotide sequencethat encodes a CDR, antibody, or antigen binding region thereof, whichbinds to at least a first aminophospholipid or anionic phospholipid,preferably PS, and which comprises at least one CDR of the antibodyproduced by the hybridoma deposited as ATCC 4545.

Further aspects of the invention concern an isolated polynucleotide thatcontains a nucleotide sequence that encodes at least one CDR that has aCDR amino acid sequence encompassed by the variable region amino acidsequence of SEQ ID NO:2 or SEQ ID NO:4, or a variant or mutagenized formthereof. Other aspects of the invention concern an isolatedpolynucleotide that contains a nucleotide sequence that encodes a CDR,antibody, or antigen binding region thereof, which binds to at least afirst aminophospholipid or anionic phospholipid, preferably PS, andwhich comprises at least one CDR with a CDR amino acid sequenceencompassed by the variable region amino acid sequence of SEQ ID NO:2 orSEQ ID NO:4, or a variant or mutagenized form thereof, wherein such avariant or mutagenized form maintains binding to the aminophospholipidor anionic phospholipid, preferably PS. The heavy chain CDR amino acidsequences encompassed by the variable region amino acid sequence of SEQID NO:2 are: VH CDR1 of SEQ ID NO:10, VH CDR2 of SEQ ID NO:11 and VHCDR3 of SEQ ID NO:12. The light chain CDR amino acid sequencesencompassed by the variable region amino acid sequence of SEQ ID NO:4are: VL CDR1 of SEQ ID NO:13, VL CDR2 of SEQ ID NO:14 and VL CDR3 of SEQID NO:15.

In other aspects of the invention, the isolated polynucleotide containsthe nucleotide sequence of SEQ ID NO:1 or SEQ ID NO:3, or a variant ormutagenized form thereof. In particular, the isolated polynucleotidecontains the nucleotide sequence of SEQ ID NO:1 or SEQ ID NO:3, or avariant or mutagenized form thereof, which nucleotide sequence encodes aCDR, antibody, or antigen binding region thereof that binds to at leasta first aminophospholipid or anionic phospholipid, preferably PS,wherein any such variant or mutagenized form maintains binding to theaminophospholipid or anionic phospholipid, preferably PS.

The present invention thus concerns polynucleotide and DNA segments,isolatable from any mammal, preferably, human or murine, that are freefrom total genomic DNA and are capable of expressing CDR regions ofanti-anionic phospholipid or anti-aminophospholipid antibody heavy andlight chains, such as 9D2 and 3G4, and preferably 3G4 (ATCC 4545), heavyand light chains. As used herein, the terms “polynucleotide segment” and“DNA segment” refer to polynucleotides and DNA molecules that have beenisolated free of total genomic DNA of a particular species. Includedwithin the term “polynucleotide segment” and “DNA segment”, are DNAsegments and smaller fragments of such segments, and also recombinantvectors, including, for example, plasmids, cosmids, phage, viruses, andthe like.

Similarly, a DNA segment comprising a coding segment or isolated geneportion encoding purified CDR regions of anti-anionic phospholipid oranti-aminophospholipid antibody heavy and light chains, such as 9D2 and3G4, and preferably 3G4, heavy and light chains, refers to a DNA segmentincluding such coding sequences and, in certain aspects, regulatorysequences, isolated substantially away from other naturally occurringgenes or protein encoding sequences. In this respect, the term “gene” isused for simplicity to refer to a functional protein, polypeptide orpeptide encoding unit. As will be understood by those in the art, thisfunctional term includes the native antibody-encoding sequences andsmaller engineered segments that express, or may be adapted to express,suitable antigen binding proteins, polypeptides or peptides.

“Isolated substantially away from other coding sequences” means that thecoding segment or isolated gene portion of interest forms thesignificant part of the coding region of the DNA segment, and that theDNA segment does not contain large portions of naturally-occurringcoding DNA, such as large chromosomal fragments or other functionalgenes or cDNA coding regions. Of course, this refers to the DNA segmentas originally isolated, and does not exclude genes or coding regionslater added to the segment by the hand of man.

In particular embodiments, the invention concerns isolated codingsegments or isolated gene portions and recombinant vectors incorporatingDNA sequences that encode variable regions of anti-anionic phospholipidor anti-aminophospholipid antibody heavy and light chains, such as 9D2and 3G4, and preferably 3G4, heavy and light chains, that comprise atleast a first sequence region that includes an amino acid sequenceregion of at least about 75%, more preferably, at least about 80%, morepreferably, at least about 85%, more preferably, at least about 90%,91%, 92%, 93%, 94%, and most preferably, at least about 95%, 96%, 97%,98% or 99% or so amino acid sequence identity to the amino acid sequenceof SEQ ID NO:2 or SEQ ID NO:4; wherein said variable regions at leastsubstantially maintain the biological properties of the variable regionsof amino acid sequences SEQ ID NO:2 or SEQ ID NO:4.

As disclosed herein, the sequences may comprise certain biologicallyfunctional equivalent amino acids or “conservative substitutions”. Othersequences may comprise functionally non-equivalent amino acids or“non-conservative substitutions” deliberately engineered to improve theproperties of the CDR or antibody containing the CDR, as is known thoseof ordinary skill in the art and further described herein.

It will also be understood that amino acid and nucleic acid sequencesmay include additional residues, such as additional N- or C-terminalamino acids or 5′ or 3′ sequences, and yet still correspond to asequence of the invention, so long as the sequence meets the criteriaset forth above, preferably including the maintenance or improvement ofbiological protein activity where protein expression is concerned. Theaddition of terminal sequences includes various non-coding sequencesflanking either of the 5′ or 3′ portions of the coding region, and alsocontrol regions.

The nucleic acid segments of the present invention may thus be combinedwith other DNA sequences, such as promoters, polyadenylation signals,additional restriction enzyme sites, multiple cloning sites, othercoding segments, and the like, such that their overall length may varyconsiderably. It is therefore contemplated that a nucleic acid fragmentof almost any length may be employed, with the total length preferablybeing limited by the ease of preparation and use in the intendedrecombinant DNA protocol.

Recombinant vectors therefore form further aspects of the presentinvention. Particularly useful vectors are contemplated to be thosevectors in which the coding portion of the DNA segment is positionedunder the control of a promoter. Generally, although not exclusively, arecombinant or heterologous promoter will be employed, i.e., a promoternot normally associated with coding sequences in their naturalenvironment. Such promoters may include bacterial, viral, eukaryotic andmammalian promoters, so long as the promoter effectively directs theexpression of the DNA segment in the cell type, organism, or evenanimal, chosen for expression.

The use of promoter and cell type combinations for protein expression isknown to those of skill in the art of molecular biology. The promotersemployed may be constitutive, or inducible, and can be used under theappropriate conditions to direct high level expression of the introducedDNA segment, such as is advantageous in the large-scale production ofrecombinant proteins or peptides.

The expression of the nucleic acid sequences of the invention may beconveniently achieved by any one or more standard techniques known thoseof ordinary skill in the art and further described herein. For example,the later description of the recombinant expression of fusion proteinsapplies equally well to antibodies and antibody fragments that are notoperatively associated with another coding sequence at the nucleic acidlevel.

E. Further Antibody Preparation Techniques

E1. Antibodies from Phagemid Libraries

Recombinant technology now allows the preparation of antibodies havingthe desired specificity from recombinant genes encoding a range ofantibodies (Van Dijk et al., 1989; incorporated herein by reference).Certain recombinant techniques involve the isolation of the antibodygenes by immunological screening of combinatorial immunoglobulin phageexpression libraries prepared from RNA isolated from the spleen of animmunized animal (Morrison et al., 1986; Winter and Milstein, 1991;Barbas et al., 1992; each incorporated herein by reference).

For such methods, combinatorial immunoglobulin phagemid libraries areprepared from RNA isolated from the spleen of the immunized animal, andphagemids expressing appropriate antibodies are selected by panningusing cells expressing the antigen and control cells. The advantages ofthis approach over conventional hybridoma techniques are thatapproximately 10⁴ times as many antibodies can be produced and screenedin a single round, and that new specificities are generated by H and Lchain combination, which further increases the percentage of appropriateantibodies generated.

One method for the generation of a large repertoire of diverse antibodymolecules in bacteria utilizes the bacteriophage lambda as the vector(Huse et al., 1989; incorporated herein by reference). Production ofantibodies using the lambda vector involves the cloning of heavy andlight chain populations of DNA sequences into separate starting vectors.The vectors are subsequently combined randomly to form a single vectorthat directs the co-expression of heavy and light chains to formantibody fragments. The heavy and light chain DNA sequences are obtainedby amplification, preferably by PCR™ or a related amplificationtechnique, of mRNA isolated from spleen cells (or hybridomas thereof)from an animal that has been immunized with a selected antigen. Theheavy and light chain sequences are typically amplified using primersthat incorporate restriction sites into the ends of the amplified DNAsegment to facilitate cloning of the heavy and light chain segments intothe starting vectors.

Another method for the generation and screening of large libraries ofwholly or partially synthetic antibody combining sites, or paratopes,utilizes display vectors derived from filamentous phage such as M13, flor fd. These filamentous phage display vectors, referred to as“phagemids”, yield large libraries of monoclonal antibodies havingdiverse and novel immunospecificities. The technology uses a filamentousphage coat protein membrane anchor domain as a means for linkinggene-product and gene during the assembly stage of filamentous phagereplication, and has been used for the cloning and expression ofantibodies from combinatorial libraries (Kang et al., 1991; Barbas etal., 1991; each incorporated herein by reference).

This general technique for filamentous phage display is described inU.S. Pat. No. 5,658,727, incorporated herein by reference. In a mostgeneral sense, the method provides a system for the simultaneous cloningand screening of pre-selected ligand-binding specificities from antibodygene repertoires using a single vector system. Screening of isolatedmembers of the library for a pre-selected ligand-binding capacity allowsthe correlation of the binding capacity of an expressed antibodymolecule with a convenient means to isolate the gene that encodes themember from the library.

Linkage of expression and screening is accomplished by the combinationof targeting of a fusion polypeptide into the periplasm of a bacterialcell to allow assembly of a functional antibody, and the targeting of afusion polypeptide onto the coat of a filamentous phage particle duringphage assembly to allow for convenient screening of the library memberof interest. Periplasmic targeting is provided by the presence of asecretion signal domain in a fusion polypeptide. Targeting to a phageparticle is provided by the presence of a filamentous phage coat proteinmembrane anchor domain (i.e., a cpIII- or cpVIII-derived membrane anchordomain) in a fusion polypeptide.

The diversity of a filamentous phage-based combinatorial antibodylibrary can be increased by shuffling of the heavy and light chaingenes, by altering one or more of the complementarity determiningregions of the cloned heavy chain genes of the library, or byintroducing random mutations into the library by error-prone polymerasechain reactions. Additional methods for screening phagemid libraries aredescribed in U.S. Pat. Nos. 5,580,717; 5,427,908; 5,403,484; and5,223,409, each incorporated herein by reference.

Another method for the screening of large combinatorial antibodylibraries has been developed, utilizing expression of populations ofdiverse heavy and light chain sequences on the surface of a filamentousbacteriophage, such as M13, fl or fd (U.S. Pat. No. 5,698,426;incorporated herein by reference). Two populations of diverse heavy (Hc)and light (Lc) chain sequences are synthesized by polymerase chainreaction (PCR™). These populations are cloned into separate M13-basedvector containing elements necessary for expression. The heavy chainvector contains a gene VIII (gVIII) coat protein sequence so thattranslation of the heavy chain sequences produces gVIII-Hc fusionproteins. The populations of two vectors are randomly combined such thatonly the vector portions containing the Hc and Lc sequences are joinedinto a single circular vector.

The combined vector directs the co-expression of both Hc and Lcsequences for assembly of the two polypeptides and surface expression onM13 (U.S. Pat. No. 5,698,426; incorporated herein by reference). Thecombining step randomly brings together different Hc and Lc encodingsequences within two diverse populations into a single vector. Thevector sequences donated from each independent vector are necessary forproduction of viable phage. Also, since the pseudo gVIII sequences arecontained in only one of the two starting vectors, co-expression offunctional antibody fragments as Lc associated gVIII-Hc fusion proteinscannot be accomplished on the phage surface until the vector sequencesare linked in the single vector.

Surface expression of the antibody library is performed in an ambersuppressor strain. An amber stop codon between the Hc sequence and thegVIII sequence unlinks the two components in a non-suppressor strain.Isolating the phage produced from the non-suppressor strain andinfecting a suppressor strain will link the Hc sequences to the gVIIIsequence during expression. Culturing the suppressor strain afterinfection allows the coexpression on the surface of M13 of all antibodyspecies within the library as gVIII fusion proteins (gVIII-Fab fusionproteins). Alternatively, the DNA can be isolated from thenon-suppressor strain and then introduced into a suppressor strain toaccomplish the same effect.

The surface expression library is screened for specific Fab fragmentsthat bind preselected molecules by standard affinity isolationprocedures. Such methods include, for example, panning (Parmley andSmith, 1988; incorporated herein by reference), affinity chromatographyand solid phase blotting procedures. Panning is preferred, because hightiters of phage can be screened easily, quickly and in small volumes.Furthermore, this procedure can select minor Fab fragments specieswithin the population, which otherwise would have been undetectable, andamplified to substantially homogenous populations. The selected Fabfragments can be characterized by sequencing the nucleic acids encodingthe polypeptides after amplification of the phage population.

Another method for producing diverse libraries of antibodies andscreening for desirable binding specificities is described in U.S. Pat.No. 5,667,988 and U.S. Pat. No. 5,759,817, each incorporated herein byreference. The method involves the preparation of libraries ofheterodimeric immunoglobulin molecules in the form of phagemid librariesusing degenerate oligonucleotides and primer extension reactions toincorporate the degeneracies into the CDR regions of the immunoglobulinvariable heavy and light chain variable domains, and display of themutagenized polypeptides on the surface of the phagemid. Thereafter, thedisplay protein is screened for the ability to bind to a preselectedantigen.

The method for producing a heterodimeric immunoglobulin moleculegenerally involves (1) introducing a heavy or light chain Vregion-coding gene of interest into the phagemid display vector; (2)introducing a randomized binding site into the phagemid display proteinvector by primer extension with an oligonucleotide containing regions ofhomology to a CDR of the antibody V region gene and containing regionsof degeneracy for producing randomized coding sequences to form a largepopulation of display vectors each capable of expressing differentputative binding sites displayed on a phagemid surface display protein;(3) expressing the display protein and binding site on the surface of afilamentous phage particle; and (4) isolating (screening) thesurface-expressed phage particle using affinity techniques such aspanning of phage particles against a preselected antigen, therebyisolating one or more species of phagemid containing a display proteincontaining a binding site that binds a preselected antigen.

A further variation of this method for producing diverse libraries ofantibodies and screening for desirable binding specificities isdescribed in U.S. Pat. No. 5,702,892, incorporated herein by reference.In this method, only heavy chain sequences are employed, the heavy chainsequences are randomized at all nucleotide positions which encode eitherthe CDRI or CDRIII hypervariable region, and the genetic variability inthe CDRs is generated independent of any biological process.

In the method, two libraries are engineered to genetically shuffleoligonucleotide motifs within the framework of the heavy chain genestructure. Through random mutation of either CDRI or CDRIII, thehypervariable regions of the heavy chain gene were reconstructed toresult in a collection of highly diverse sequences. The heavy chainproteins encoded by the collection of mutated gene sequences possessedthe potential to have all of the binding characteristics of animmunoglobulin while requiring only one of the two immunoglobulinchains.

Specifically, the method is practiced in the absence of theimmunoglobulin light chain protein. A library of phage displayingmodified heavy chain proteins is incubated with an immobilized ligand toselect clones encoding recombinant proteins that specifically bind theimmobilized ligand. The bound phage are then dissociated from theimmobilized ligand and amplified by growth in bacterial host cells.Individual viral plaques, each expressing a different recombinantprotein, are expanded, and individual clones can then be assayed forbinding activity.

E2. Antibodies from Human Lymphocytes

Antibodies against phospholipids occur in the human population. However,these antibodies are typically associated with disease and their use inthe present invention should preferably be avoided. However, humanlymphocytes from healthy subjects can be used as appropriate as startingmaterials for generating an antibody for use in the invention.

In vitro immunization, or antigen stimulation, may also be used togenerate a human antibody for use in the present invention. Suchtechniques can be used to stimulate peripheral blood lymphocytes fromnormal, healthy subjects simply by stimulating antibody-producing cellswith anionic phospholipids and aminophospholipids in vitro.

Such “in vitro immunization” involves antigen-specific activation ofnon-immunized B lymphocytes, generally within a mixed population oflymphocytes (mixed lymphocyte cultures, MLC). In vitro immunizations mayalso be supported by B cell growth and differentiation factors andlymphokines. The antibodies produced by these methods are often IgMantibodies (Borrebaeck and Moller, 1986; incorporated herein byreference).

Another method has been described (U.S. Pat. No. 5,681,729, incorporatedherein by reference) wherein human lymphocytes that mainly produce IgG(or IgA) antibodies can be obtained. The method involves, in a generalsense, transplanting human lymphocytes to an immunodeficient animal sothat the human lymphocytes “take” in the animal body; immunizing theanimal with a desired antigen, so as to generate human lymphocytesproducing an antibody specific to the antigen; and recovering the humanlymphocytes producing the antibody from the animal. The humanlymphocytes thus produced can be used to produce a monoclonal antibodyby immortalizing the human lymphocytes producing the antibody, cloningthe obtained immortalized human-originated lymphocytes producing theantibody, and recovering a monoclonal antibody specific to the desiredantigen from the cloned immortalized human-originated lymphocytes.

The immunodeficient animals that may be employed in this technique arethose that do not exhibit rejection when human lymphocytes aretransplanted to the animals. Such animals may be artificially preparedby physical, chemical or biological treatments. Any immunodeficientanimal may be employed. The human lymphocytes may be obtained from humanperipheral blood, spleen, lymph nodes, tonsils or the like.

The “taking” of the transplanted human lymphocytes in the animals can beattained by merely administering the human lymphocytes to the animals.The administration route is not restricted and may be, for example,subcutaneous, intravenous or intraperitoneal. The dose of the humanlymphocytes is not restricted, and can usually be 10⁶ to 10⁸ lymphocytesper animal. The immunodeficient animal is then immunized with thedesired antigen.

After the immunization, human lymphocytes are recovered from the blood,spleen, lymph nodes or other lymphatic tissues by any conventionalmethod. For example, mononuclear cells can be separated by theFicoll-Hypaque (specific gravity: 1.077) centrifugation method, and themonocytes removed by the plastic dish adsorption method. Thecontaminating cells originating from the immunodeficient animal may beremoved by using an antiserum specific to the animal cells. Theantiserum may be obtained by, for example, immunizing a second, distinctanimal with the spleen cells of the immunodeficient animal, andrecovering serum from the distinct immunized animal. The treatment withthe antiserum may be carried out at any stage. The human lymphocytes mayalso be recovered by an immunological method employing a humanimmunoglobulin expressed on the cell surface as a marker.

By these methods, human lymphocytes mainly producing IgG and IgAantibodies specific to one or more selected anionic phospholipids andaminophospholipids can be obtained. Monoclonal antibodies are thenobtained from the human lymphocytes by immortalization, selection, cellgrowth and antibody production.

E3. Transgenic Mice Containing Human Antibody Libraries

Recombinant technology is now available for the preparation ofantibodies. In addition to the combinatorial immunoglobulin phageexpression libraries disclosed above, another molecular cloning approachis to prepare antibodies from transgenic mice containing human antibodylibraries. Such techniques are described in U.S. Pat. No. 5,545,807,incorporated herein by reference.

In a most general sense, these methods involve the production of atransgenic animal that has inserted into its germline genetic materialthat encodes for at least part of an immunoglobulin of human origin orthat can rearrange to encode a repertoire of immunoglobulins. Theinserted genetic material may be produced from a human source, or may beproduced synthetically. The material may code for at least part of aknown immunoglobulin or may be modified to code for at least part of analtered immunoglobulin.

The inserted genetic material is expressed in the transgenic animal,resulting in production of an immunoglobulin derived at least in partfrom the inserted human immunoglobulin genetic material. It is found thegenetic material is rearranged in the transgenic animal, so that arepertoire of immunoglobulins with part or parts derived from insertedgenetic material may be produced, even if the inserted genetic materialis incorporated in the germline in the wrong position or with the wronggeometry.

The inserted genetic material may be in the form of DNA cloned intoprokaryotic vectors such as plasmids and/or cosmids. Larger DNAfragments are inserted using yeast artificial chromosome vectors (Burkeet al., 1987; incorporated herein by reference), or by introduction ofchromosome fragments (Richer and Lo, 1989; incorporated herein byreference). The inserted genetic material may be introduced to the hostin conventional manner, for example by injection or other proceduresinto fertilized eggs or embryonic stem cells.

In preferred aspects, a host animal that initially does not carrygenetic material encoding immunoglobulin constant regions is utilized,so that the resulting transgenic animal will use only the inserted humangenetic material when producing immunoglobulins. This can be achievedeither by using a naturally occurring mutant host lacking the relevantgenetic material, or by artificially making mutants e.g., in cell linesultimately to create a host from which the relevant genetic material hasbeen removed.

Where the host animal carries genetic material encoding immunoglobulinconstant regions, the transgenic animal will carry the naturallyoccurring genetic material and the inserted genetic material and willproduce immunoglobulins derived from the naturally occurring geneticmaterial, the inserted genetic material, and mixtures of both types ofgenetic material. In this case the desired immunoglobulin can beobtained by screening hybridomas derived from the transgenic animal,e.g., by exploiting the phenomenon of allelic exclusion of antibody geneexpression or differential chromosome loss.

Once a suitable transgenic animal has been prepared, the animal issimply immunized with the desired immunogen. Depending on the nature ofthe inserted material, the animal may produce a chimeric immunoglobulin,e.g. of mixed mouse/human origin, where the genetic material of foreignorigin encodes only part of the immunoglobulin; or the animal mayproduce an entirely foreign immunoglobulin, e.g. of wholly human origin,where the genetic material of foreign origin encodes an entireimmunoglobulin.

Polyclonal antisera may be produced from the transgenic animal followingimmunization. Immunoglobulin-producing cells may be removed from theanimal to produce the immunoglobulin of interest. Preferably, monoclonalantibodies are produced from the transgenic animal, e.g., by fusingspleen cells from the animal with myeloma cells and screening theresulting hybridomas to select those producing the desired antibody.Suitable techniques for such processes are described herein.

In an alternative approach, the genetic material may be incorporated inthe animal in such a way that the desired antibody is produced in bodyfluids such as serum or external secretions of the animal, such as milk,colostrum or saliva. For example, by inserting in vitro genetic materialencoding for at least part of a human immunoglobulin into a gene of amammal coding for a milk protein and then introducing the gene to afertilized egg of the mammal, e.g., by injection, the egg may developinto an adult female mammal producing milk containing immunoglobulinderived at least in part from the inserted human immunoglobulin geneticmaterial. The desired antibody can then be harvested from the milk.Suitable techniques for carrying out such processes are known to thoseskilled in the art.

The foregoing transgenic animals are usually employed to produce humanantibodies of a single isotype, more specifically an isotype that isessential for B cell maturation, such as IgM and possibly IgD. Anotherpreferred method for producing human antibodies is described in U.S.Pat. Nos. 5,545,806; 5,569,825; 5,625,126; 5,633,425; 5,661,016; and5,770,429; each incorporated by reference, wherein transgenic animalsare described that are capable of switching from an isotype needed for Bcell development to other isotypes.

In the development of a B lymphocyte, the cell initially produces IgMwith a binding specificity determined by the productively rearrangedV_(H) and V_(L) regions. Subsequently, each B cell and its progeny cellssynthesize antibodies with the same L and H chain V regions, but theymay switch the isotype of the H chain. The use of mu or delta constantregions is largely determined by alternate splicing, permitting IgM andIgD to be coexpressed in a single cell. The other heavy chain isotypes(gamma, alpha, and epsilon) are only expressed natively after a generearrangement event deletes the C mu and C delta exons. This generearrangement process, termed isotype switching, typically occurs byrecombination between so called switch segments located immediatelyupstream of each heavy chain gene (except delta). The individual switchsegments are between 2 and 10 kb in length, and consist primarily ofshort repeated sequences.

For these reasons, it is preferable that transgenes incorporatetranscriptional regulatory sequences within about 1-2 kb upstream ofeach switch region that is to be utilized for isotype switching. Thesetranscriptional regulatory sequences preferably include a promoter andan enhancer element, and more preferably include the 5′ flanking (i.e.,upstream) region that is naturally associated (i.e., occurs in germlineconfiguration) with a switch region. Although a 5′ flanking sequencefrom one switch region can be operably linked to a different switchregion for transgene construction, in some embodiments it is preferredthat each switch region incorporated in the transgene construct have the5′ flanking region that occurs immediately upstream in the naturallyoccurring germline configuration. Sequence information relating toimmunoglobulin switch region sequences is known (Mills et al., 1990;Sideras et al., 1989; each incorporated herein by reference).

In the method described in U.S. Pat. Nos. 5,545,806; 5,569,825;5,625,126; 5,633,425; 5,661,016; and 5,770,429, the human immunoglobulintransgenes contained within the transgenic animal function correctlythroughout the pathway of B-cell development, leading to isotypeswitching. Accordingly, in this method, these transgenes are constructedso as to produce isotype switching and one or more of the following: (1)high level and cell-type specific expression, (2) functional generearrangement, (3) activation of and response to allelic exclusion, (4)expression of a sufficient primary repertoire, (5) signal transduction,(6) somatic hypermutation, and (7) domination of the transgene antibodylocus during the immune response.

An important requirement for transgene function is the generation of aprimary antibody repertoire that is diverse enough to trigger asecondary immune response for a wide range of antigens. The rearrangedheavy chain gene consists of a signal peptide exon, a variable regionexon and a tandem array of multi-domain constant region regions, each ofwhich is encoded by several exons. Each of the constant region genesencode the constant portion of a different class of immunoglobulins.During B-cell development, V region proximal constant regions aredeleted leading to the expression of new heavy chain classes. For eachheavy chain class, alternative patterns of RNA splicing give rise toboth transmembrane and secreted immunoglobulins.

The human heavy chain locus consists of approximately 200 V genesegments spanning 2 Mb, approximately 30 D gene segments spanning about40 kb, six J segments clustered within a 3 kb span, and nine constantregion gene segments spread out over approximately 300 kb. The entirelocus spans approximately 2.5 Mb of the distal portion of the long armof chromosome 14. Heavy chain transgene fragments containing members ofall six of the known V_(H) families, the D and J gene segments, as wellas the mu, delta, gamma 3, gamma 1 and alpha 1 constant regions areknown (Berman et al., 1988; incorporated herein by reference). Genomicfragments containing all of the necessary gene segments and regulatorysequences from a human light chain locus is similarly constructed.

The expression of successfully rearranged immunoglobulin heavy and lighttransgenes usually has a dominant effect by suppressing therearrangement of the endogenous immunoglobulin genes in the transgenicnonhuman animal. However, in certain embodiments, it is desirable toeffect complete inactivation of the endogenous Ig loci so that hybridimmunoglobulin chains comprising a human variable region and a non-human(e.g., murine) constant region cannot be formed, for example bytrans-switching between the transgene and endogenous Ig sequences. Usingembryonic stem cell technology and homologous recombination, theendogenous immunoglobulin repertoire can be readily eliminated. Inaddition, suppression of endogenous Ig genes may be accomplished using avariety of techniques, such as antisense technology.

In other aspects of the invention, it may be desirable to produce atrans-switched immunoglobulin. Antibodies comprising such chimerictrans-switched immunoglobulins can be used for a variety of applicationswhere it is desirable to have a non-human (e.g., murine) constantregion, e.g., for retention of effector functions in the host. Thepresence of a murine constant region can afford advantages over a humanconstant region, for example, to provide murine effector functions(e.g., ADCC, murine complement fixation) so that such a chimericantibody may be tested in a mouse disease model. Subsequent to theanimal testing, the human variable region encoding sequence may beisolated, e.g., by PCR amplification or cDNA cloning from the source(hybridoma clone), and spliced to a sequence encoding a desired humanconstant region to encode a human sequence antibody more suitable forhuman therapeutic use.

E4. Humanized Antibodies

Human antibodies generally have at least three potential advantages foruse in human therapy. First, because the effector portion is human, itmay interact better with the other parts of the human immune system,e.g., to destroy target cells more efficiently by complement-dependentcytotoxicity (CDC) or antibody-dependent cellular cytotoxicity (ADCC).Second, the human immune system should not recognize the antibody asforeign. Third, the half-life in the human circulation will be similarto naturally occurring human antibodies, allowing smaller and lessfrequent doses to be given.

Various methods for preparing human antibodies are provided herein. Inaddition to human antibodies, “humanized” antibodies have manyadvantages. “Humanized” antibodies are generally chimeric or mutantmonoclonal antibodies from mouse, rat, hamster, rabbit or other species,bearing human constant and/or variable region domains or specificchanges. Techniques for generating a so-called “humanized” antibody arewell known to those of skill in the art.

Humanized antibodies also share the foregoing advantages. First, theeffector portion is still human. Second, the human immune system shouldnot recognize the framework or constant region as foreign, and thereforethe antibody response against such an injected antibody should be lessthan against a totally foreign mouse antibody. Third, injected humanizedantibodies, as opposed to injected mouse antibodies, will presumablyhave a half-life more similar to naturally occurring human antibodies,also allowing smaller and less frequent doses.

A number of methods have been described to produce humanized antibodies.Controlled rearrangement of antibody domains joined through proteindisulfide bonds to form new, artificial protein molecules or “chimeric”antibodies can be utilized (Konieczny et al., 1981; incorporated hereinby reference). Recombinant DNA technology can also be used to constructgene fusions between DNA sequences encoding mouse antibody variablelight and heavy chain domains and human antibody light and heavy chainconstant domains (Morrison et al., 1984; incorporated herein byreference).

DNA sequences encoding the antigen binding portions or complementaritydetermining regions (CDR's) of murine monoclonal antibodies can begrafted by molecular means into the DNA sequences encoding theframeworks of human antibody heavy and light chains (Jones et al., 1986;Riechmann et al., 1988; each incorporated herein by reference). Theexpressed recombinant products are called “reshaped” or humanizedantibodies, and comprise the framework of a human antibody light orheavy chain and the antigen recognition portions, CDR's, of a murinemonoclonal antibody.

Another method for producing humanized antibodies is described in U.S.Pat. No. 5,639,641, incorporated herein by reference. The methodprovides, via resurfacing, humanized rodent antibodies that haveimproved therapeutic efficacy due to the presentation of a human surfacein the variable region. In the method: (1) position alignments of a poolof antibody heavy and light chain variable regions is generated to givea set of heavy and light chain variable region framework surface exposedpositions, wherein the alignment positions for all variable regions areat least about 98% identical; (2) a set of heavy and light chainvariable region framework surface exposed amino acid residues is definedfor a rodent antibody (or fragment thereof); (3) a set of heavy andlight chain variable region framework surface exposed amino acidresidues that is most closely identical to the set of rodent surfaceexposed amino acid residues is identified; (4) the set of heavy andlight chain variable region framework surface exposed amino acidresidues defined in step (2) is substituted with the set of heavy andlight chain variable region framework surface exposed amino acidresidues identified in step (3), except for those amino acid residuesthat are within 5 Å of any atom of any residue of the complementaritydetermining regions of the rodent antibody; and (5) the humanized rodentantibody having binding specificity is produced.

A similar method for the production of humanized antibodies is describedin U.S. Pat. Nos. 5,693,762; 5,693,761; 5,585,089; and 5,530,101, eachincorporated herein by reference. These methods involve producinghumanized immunoglobulins having one or more complementarity determiningregions (CDR's) and possible additional amino acids from a donorimmunoglobulin and a framework region from an accepting humanimmunoglobulin. Each humanized immunoglobulin chain usually comprises,in addition to the CDR's, amino acids from the donor immunoglobulinframework that are capable of interacting with the CDR's to effectbinding affinity, such as one or more amino acids that are immediatelyadjacent to a CDR in the donor immunoglobulin or those within about 3 Åas predicted by molecular modeling. The heavy and light chains may eachbe designed by using any one, any combination, or all of the variousposition criteria described in U.S. Pat. Nos. 5,693,762; 5,693,761;5,585,089; and 5,530,101, each incorporated herein by reference. Whencombined into an intact antibody, the humanized immunoglobulins aresubstantially non-immunogenic in humans and retain substantially thesame affinity as the donor immunoglobulin to the original antigen.

An additional method for producing humanized antibodies is described inU.S. Pat. Nos. 5,565,332 and 5,733,743, each incorporated herein byreference. This method combines the concept of humanizing antibodieswith the phagemid libraries also described in detail herein. In ageneral sense, the method utilizes sequences from the antigen bindingsite of an antibody or population of antibodies directed against anantigen of interest. Thus for a single rodent antibody, sequencescomprising part of the antigen binding site of the antibody may becombined with diverse repertoires of sequences of human antibodies thatcan, in combination, create a complete antigen binding site.

The antigen binding sites created by this process differ from thosecreated by CDR grafting, in that only the portion of sequence of theoriginal rodent antibody is likely to make contacts with antigen in asimilar manner. The selected human sequences are likely to differ insequence and make alternative contacts with the antigen from those ofthe original binding site. However, the constraints imposed by bindingof the portion of original sequence to antigen and the shapes of theantigen and its antigen binding sites, are likely to drive the newcontacts of the human sequences to the same region or epitope of theantigen. This process has therefore been termed “epitope imprintedselection” (EIS).

Starting with an animal antibody, one process results in the selectionof antibodies that are partly human antibodies. Such antibodies may besufficiently similar in sequence to human antibodies to be used directlyin therapy or after alteration of a few key residues. Sequencedifferences between the rodent component of the selected antibody withhuman sequences could be minimized by replacing those residues thatdiffer with the residues of human sequences, for example, by sitedirected mutagenesis of individual residues, or by CDR grafting ofentire loops. However, antibodies with entirely human sequences can alsobe created. EIS therefore offers a method for making partly human orentirely human antibodies that bind to the same epitope as animal orpartly human antibodies respectively. In EIS, repertoires of antibodyfragments can be displayed on the surface of filamentous phase and thegenes encoding fragments with antigen binding activities selected bybinding of the phage to antigen.

Additional methods for humanizing antibodies contemplated for use in thepresent invention are described in U.S. Pat. Nos. 5,750,078; 5,502,167;5,705,154; 5,770,403; 5,698,417; 5,693,493; 5,558,864; 4,935,496; and4,816,567, each incorporated herein by reference.

E5. Mutagenesis by PCR™

Site-specific mutagenesis is a technique useful in the preparation ofindividual antibodies through specific mutagenesis of the underlyingDNA. The technique further provides a ready ability to prepare and testsequence variants, incorporating one or more of the foregoingconsiderations, whether humanizing or not, by introducing one or morenucleotide sequence changes into the DNA.

Although many methods are suitable for use in mutagenesis, the use ofthe polymerase chain reaction (PCR™) is generally now preferred. Thistechnology offers a quick and efficient method for introducing desiredmutations into a given DNA sequence. The following text particularlydescribes the use of PCR™ to introduce point mutations into a sequence,as may be used to change the amino acid encoded by the given sequence.Adaptations of this method are also suitable for introducing restrictionenzyme sites into a DNA molecule.

In this method, synthetic oligonucleotides are designed to incorporate apoint mutation at one end of an amplified segment. Following PCR™, theamplified fragments are blunt-ended by treating with Klenow fragments,and the blunt-ended fragments are then ligated and subcloned into avector to facilitate sequence analysis.

To prepare the template DNA that one desires to mutagenize, the DNA issubcloned into a high copy number vector, such as pUC19, usingrestriction sites flanking the area to be mutated. Template DNA is thenprepared using a plasmid miniprep. Appropriate oligonucleotide primersthat are based upon the parent sequence, but which contain the desiredpoint mutation and which are flanked at the 5′ end by a restrictionenzyme site, are synthesized using an automated synthesizer. It isgenerally required that the primer be homologous to the template DNA forabout 15 bases or so. Primers may be purified by denaturingpolyacrylamide gel electrophoresis, although this is not absolutelynecessary for use in PCR™. The 5′ end of the oligonucleotides shouldthen be phosphorylated.

The template DNA should be amplified by PCR™, using the oligonucleotideprimers that contain the desired point mutations. The concentration ofMgCl₂ in the amplification buffer will generally be about 15 mM.Generally about 20-25 cycles of PCR™ should be carried out as follows:denaturation, 35 sec. at 95° C.; hybridization, 2 min. at 50° C.; andextension, 2 min. at 72° C. The PCR™ will generally include a last cycleextension of about 10 min. at 72° C. After the final extension step,about 5 units of Klenow fragments should be added to the reactionmixture and incubated for a further 15 min. at about 30° C. Theexonuclease activity of the Klenow fragments is required to make theends flush and suitable for blunt-end cloning.

The resultant reaction mixture should generally be analyzed bynondenaturing agarose or acrylamide gel electrophoresis to verify thatthe amplification has yielded the predicted product. One would thenprocess the reaction mixture by removing most of the mineral oils,extracting with chloroform to remove the remaining oil, extracting withbuffered phenol and then concentrating by precipitation with 100%ethanol. Next, one should digest about half of the amplified fragmentswith a restriction enzyme that cuts at the flanking sequences used inthe oligonucleotides. The digested fragments are purified on a lowgelling/melting agarose gel.

To subclone the fragments and to check the point mutation, one wouldsubclone the two amplified fragments into an appropriately digestedvector by blunt-end ligation. This would be used to transform E. coli,from which plasmid DNA could subsequently be prepared using a miniprep.The amplified portion of the plasmid DNA would then be analyzed by DNAsequencing to confirm that the correct point mutation was generated.This is important as Taq DNA polymerase can introduce additionalmutations into DNA fragments.

The introduction of a point mutation can also be effected usingsequential PCR™ steps. In this procedure, the two fragments encompassingthe mutation are annealed with each other and extended by mutuallyprimed synthesis. This fragment is then amplified by a second PCR™ step,thereby avoiding the blunt-end ligation required in the above protocol.In this method, the preparation of the template DNA, the generation ofthe oligonucleotide primers and the first PCR™ amplification areperformed as described above. In this process, however, the chosenoligonucleotides should be homologous to the template DNA for a stretchof between about 15 and about 20 bases and must also overlap with eachother by about 10 bases or more.

In the second PCR™ amplification, one would use each amplified fragmentand each flanking sequence primer and carry PCR™ for between about 20and about 25 cycles, using the conditions as described above. One wouldagain subclone the fragments and check that the point mutation wascorrect by using the steps outlined above.

In using either of the foregoing methods, it is generally preferred tointroduce the mutation by amplifying as small a fragment as possible. Ofcourse, parameters such as the melting temperature of theoligonucleotide, as will generally be influenced by the GC content andthe length of the oligo, should also be carefully considered. Theexecution of these methods, and their optimization if necessary, will beknown to those of skill in the art, and are further described in variouspublications, such as Current Protocols in Molecular Biology, 1995,incorporated herein by reference.

When performing site-specific mutagenesis, Table A can be employed as areference.

TABLE A Amino Acids Codons Alanine Ala A GCA GCC GCG GCU Cysteine Cys CUGC UGU Aspartic acid Asp D GAC GAU Glutamic acid Glu E GAA GAGPhenylalanine Phe F UUC UUU Glycine Gly G GGA GGC GGG GGU Histidine HisH CAC CAU Isoleucine Ile I AUA AUC AUU Lysine Lys K AAA AAG Leucine LeuL UUA UUG CUA CUC CUG CUU Methionine Met M AUG Asparagine Asn N AAC AAUProline Pro P CCA CCC CCG CCU Glutamine Gln Q CAA CAG Arginine Arg R AGAAGG CGA CGC CGG CGU Serine Ser S AGC AGU UCA UCC UCG UCU Threonine Thr TACA ACC ACG ACU Valine Val V GUA GUC GUG GUU Tryptophan Trp W UGGTyrosine Tyr Y UAC UAU

E6. Antibody Fragments and Derivatives

Irrespective of the source of the original antibody against an anionicphospholipid or aminophospholipids, either the intact antibody, antibodymultimers, or any one of a variety of functional, antigen-bindingregions of the antibody may be used in the present invention. Exemplaryfunctional regions include scFv, Fv, Fab′, Fab and F(ab′)₂ fragments ofantibodies. Techniques for preparing such constructs are well known tothose in the art and are further exemplified herein.

The choice of antibody construct may be influenced by various factors.For example, prolonged half-life can result from the active readsorptionof intact antibodies within the kidney, a property of the Fc piece ofimmunoglobulin. IgG based antibodies, therefore, are expected to exhibitslower blood clearance than their Fab′ counterparts. However, Fab′fragment-based compositions will generally exhibit better tissuepenetrating capability.

Antibody fragments can be obtained by proteolysis of the wholeimmunoglobulin by the non-specific thiol protease, papain. Papaindigestion yields two identical antigen-binding fragments, termed “Fabfragments”, each with a single antigen-binding site, and a residual “Fcfragment”.

Papain should first be activated by reducing the sulphydryl group in theactive site with cysteine, 2-mercaptoethanol or dithiothreitol. Heavymetals in the stock enzyme should be removed by chelation with EDTA (2mM) to ensure maximum enzyme activity. Enzyme and substrate are normallymixed together in the ratio of 1:100 by weight. After incubation, thereaction can be stopped by irreversible alkylation of the thiol groupwith iodoacetamide or simply by dialysis. The completeness of thedigestion should be monitored by SDS-PAGE and the various fractionsseparated by protein A-Sepharose or ion exchange chromatography.

The usual procedure for preparation of F(ab′)₂ fragments from IgG ofrabbit and human origin is limited proteolysis by the enzyme pepsin. Theconditions, 100× antibody excess w/w in acetate buffer at pH 4.5, 37°C., suggest that antibody is cleaved at the C-terminal side of theinter-heavy-chain disulfide bond. Rates of digestion of mouse IgG mayvary with subclass and it may be difficult to obtain high yields ofactive F(ab′)₂ fragments without some undigested or completely degradedIgG. In particular, IgG_(2b) is highly susceptible to completedegradation. The other subclasses require different incubationconditions to produce optimal results, all of which is known in the art.

Pepsin treatment of intact antibodies yields an F(ab′)₂ fragment thathas two antigen-combining sites and is still capable of cross-linkingantigen. Digestion of rat IgG by pepsin requires conditions includingdialysis in 0.1 M acetate buffer, pH 4.5, and then incubation for fourhours with 1% w/w pepsin; IgG₁ and IgG_(2a) digestion is improved iffirst dialyzed against 0.1 M formate buffer, pH 2.8, at 4° C., for 16hours followed by acetate buffer. IgG_(2b) gives more consistent resultswith incubation in staphylococcal V8 protease (3% w/w) in 0.1 M sodiumphosphate buffer, pH 7.8, for four hours at 37° C.

An Fab fragment also contains the constant domain of the light chain andthe first constant domain (CH1) of the heavy chain. Fab′ fragmentsdiffer from Fab fragments by the addition of a few residues at thecarboxyl terminus of the heavy chain CH1 domain including one or morecysteine(s) from the antibody hinge region. F(ab′)₂ antibody fragmentswere originally produced as pairs of Fab′ fragments that have hingecysteines between them. Other chemical couplings of antibody fragmentsare also known.

An “Fv” fragment is the minimum antibody fragment that contains acomplete antigen-recognition and binding site. This region consists of adimer of one heavy chain and one light chain variable domain in tight,con-covalent association. It is in this configuration that the threehypervariable regions of each variable domain interact to define anantigen-binding site on the surface of the V_(H)-V_(L) dimer.Collectively, the six hypervariable regions confer antigen-bindingspecificity to the antibody. However, even a single variable domain (orhalf of an Fv comprising only three hypervariable regions specific foran antigen) has the ability to recognize and bind antigen, although at alower affinity than the entire binding site.

“Single-chain Fv” or “scFv” antibody fragments (now also known as“single chains”) comprise the V_(H) and V_(L) domains of an antibody,wherein these domains are present in a single polypeptide chain.Generally, the Fv polypeptide further comprises a polypeptide linkerbetween the V_(H) and V_(L) domains that enables the sFv to form thedesired structure for antigen binding.

The following patents are specifically incorporated herein by referencefor the purposes of even further supplementing the present teachingsregarding the preparation and use of functional, antigen-binding regionsof antibodies, including scFv, Fv, Fab′, Fab and F(ab′)₂ fragments ofantibodies: U.S. Pat. Nos. 5,855,866; 5,877,289; 5,965,132; 6,093,399;6,261,535 and 6,004,555. WO 98/45331 is also incorporated herein byreference for purposes including even further describing and teachingthe preparation of variable, hypervariable and complementaritydetermining (CDR) regions of antibodies. Moreover, the successfulproduction of scFv constructs within the scope of the present inventionis detailed in Example XIV.

“Diabodies” are small antibody fragments with two antigen-binding sites,which fragments comprise a heavy chain variable domain (V_(H)) connectedto a light chain variable domain (V_(L)) in the same polypeptide chain(V_(H)-V_(L)). By using a linker that is too short to allow pairingbetween the two domains on the same chain, the domains are forced topair with the complementary domains of another chain and create twoantigen-binding sites. Diabodies are described in EP 404,097 and WO93/11161, each specifically incorporated herein by reference. “Linearantibodies”, which can be bispecific or monospecific, comprise a pair oftandem Fd segments (V_(H)-C_(H)1-V_(H)-C_(H)1) that form a pair ofantigen binding regions, as described in Zapata et al. (1995),specifically incorporated herein by reference.

In using a Fab′ or antigen binding fragment of an antibody, with theattendant benefits on tissue penetration, one may derive additionaladvantages from modifying the fragment to increase its half-life. Avariety of techniques may be employed, such as manipulation ormodification of the antibody molecule itself, and also conjugation toinert carriers. Any conjugation for the sole purpose of increasinghalf-life, rather than to deliver an agent to a target, should beapproached carefully in that Fab′ and other fragments are chosen topenetrate tissues. Nonetheless, conjugation to non-protein polymers,such PEG and the like, is contemplated.

Modifications other than conjugation are therefore based upon modifyingthe structure of the antibody fragment to render it more stable, and/orto reduce the rate of catabolism in the body. One mechanism for suchmodifications is the use of D-amino acids in place of L-amino acids.Those of ordinary skill in the art will understand that the introductionof such modifications needs to be followed by rigorous testing of theresultant molecule to ensure that it still retains the desiredbiological properties. Further stabilizing modifications include the useof the addition of stabilizing moieties to either the N-terminal or theC-terminal, or both, which is generally used to prolong the half-life ofbiological molecules. By way of example only, one may wish to modify thetermini by acylation or amination.

Moderate conjugation-type modifications for use with the presentinvention include incorporating a salvage receptor binding epitope intothe antibody fragment. Techniques for achieving this include mutation ofthe appropriate region of the antibody fragment or incorporating theepitope as a peptide tag that is attached to the antibody fragment. WO96/32478 is specifically incorporated herein by reference for thepurposes of further exemplifying such technology. Salvage receptorbinding epitopes are typically regions of three or more amino acids fromone or two lops of the Fc domain that are transferred to the analogousposition on the antibody fragment. The salvage receptor binding epitopesof WO 98/45331 are incorporated herein by reference for use with thepresent invention.

F. Immunoconjugates Binding to Anionic Phospholipids andAminophospholipids

The present inventors earlier developed a range of immunoconjugates thatbind to aminophospholipids for use in targeting tumor vasculature (U.S.Pat. No. 6,312,694, specifically incorporated herein by reference).These agents use aminophospholipid-binding proteins, such as annexinsand kininogens, and antibodies against aminophospholipids, such as PSand PE, to deliver attached therapeutic agents to tumor and intratumoralvasculature. The present invention now provides selected anti-PSantibodies with improved properties, such as 3G4 (ATCC 4545) and 9D2,and these and competing antibodies can now also be used as the antibodyportions of immunoconjugates.

In addition to the use of vascular targeting agents that bind toaminophospholipids (U.S. Pat. No. 6,312,694), the present discovery thatanionic phospholipids, as well as aminophospholipids, are stable andtargetable entities within tumor vasculature provides for the use of arange of new tumor vascular targeting agents. The new compounds, notsuggested in the earlier work directed to aminophospholipids, useantibodies directed against anionic phospholipids to deliver toxins,cytokines, coagulants and other therapeutic agents to anionicphospholipids upregulated on tumor and intratumoral vasculature. Asdetailed above in regard to the naked antibodies, the development ofthese aspects of the invention required the generation of biologicaltools, particularly antibodies, with exquisite specificity for differentphospholipids, anionic phospholipids and aminophospholipids.

As the present invention shows that anionic phospholipids andaminophospholipids, such as PS, PE, PI, PA and PG, and most particularlyPS and PE, are safe and effective targets for anti-viral therapy,antibodies and peptides that bind to these components, particularly PSand PE, may now be advantageously linked to a range of known anti-viralagents. These anti-viral conjugates include both peptide-based andantibody-based conjugates, the latter of which may be termed anti-viralimmunoconjugates or “immunovirocides”.

In these aspects of the invention, any antibody against an anionicphospholipid can be used to prepare an immunoconjugate, immunotoxin orcoaguligand, with antibodies such as the second generation antibodies,particularly 9D2-like and 3G4-like antibodies, with their advantageousanionic phospholipid binding profiles, being preferred. Agents for usein such immunoconjugates preferably include anti-cellular or cytotoxicagents, coagulants (coagulation factors), cytokines, radiotherapeuticagents, anti-angiogenic agents, apoptosis-inducing agents, anti-tubulindrugs and anti-viral agents (and the PE-binding peptides, such asduramycin derivatives, as disclosed in detail herein). In the anti-viralimmunoconjugates, there is no requirement to use a second generationantibody as disclosed herein, although these can certainly be employed.Any antibody to aminophospholipids or anionic phospholipids may be thusbe linked to an anti-viral agent to form an anti-viral immunoconjugatesor immunovirocide in accordance with the present invention.

F1. Anti-Cellular and Cytotoxic Agents

For certain applications, the therapeutic agents will be cytotoxic orpharmacological agents, particularly cytotoxic, cytostatic or otherwiseanti-cellular agents having the ability to kill or suppress the growthor cell division of cells, particularly tumor endothelial cells or tumorcells. In general, these aspects of the invention contemplate the use ofany pharmacological agent that can be conjugated to an antibody againstan anionic phospholipid, preferably a 9D2-based or 3G4-based antibody,and delivered in active form to the targeted endothelium.

Exemplary anti-cellular agents include chemotherapeutic agents, as wellas cytotoxins. Chemotherapeutic agents that may be used include:hormones, such as steroids; anti-metabolites, such as cytosinearabinoside, fluorouracil, methotrexate or aminopterin; anthracyclines;mitomycin C; vinca alkaloids; demecolcine; etoposide; mithramycin;anti-tumor alkylating agents, such as chlorambucil or melphalan. Otherembodiments may include agents such as cytokines. Basically, anyanti-cellular agent may be used, so long as it can be successfullyconjugated to, or associated with, an antibody in a manner that willallow its targeting, internalization, release and/or presentation toblood components at the site of the targeted cells, such as endothelialcells.

There may be circumstances, such as when the target antigen does notinternalize by a route consistent with efficient intoxication by thetoxic compound, where one will desire to target chemotherapeutic agents,such as anti-tumor drugs, cytokines, antimetabolites, alkylating agents,hormones, and the like. A variety of chemotherapeutic and otherpharmacological agents have now been successfully conjugated toantibodies and shown to function pharmacologically, includingdoxorubicin, daunomycin, methotrexate, vinblastine, neocarzinostatin,macromycin, trenimon and α-amanitin.

In other circumstances, any potential side-effects from cytotoxin-basedtherapy may be eliminated by the use of DNA synthesis inhibitors, suchas daunorubicin, doxorubicin, adriamycin, and the like. These agents aretherefore preferred examples of anti-cellular agents for use in certainaspects of the present invention. In terms of cytostatic agents, suchcompounds generally disturb the natural cell cycle of a target cell,preferably so that the cell is taken out of the cell cycle.

A wide variety of cytotoxic agents are known that may be conjugated toan antibody against an anionic phospholipid, preferably a 9D2-based or3G4-based antibody. Examples include numerous useful plant-, fungus- orbacteria-derived toxins, which, by way of example, include various Achain toxins, particularly ricin A chain; ribosome inactivatingproteins, such as saporin or gelonin; α-sarcin; aspergillin;restrictocin; ribonucleases, such as placental ribonuclease; diphtheriatoxin; and pseudomonas exotoxin, to name just a few.

Of the toxins, the use of gelonin and ricin A chains are preferred. Theuse of gelonin as the effector or toxin portion of immunoconjugates thatbind to markers expressed, accessible to binding, adsorbed or localizedon intratumoral blood vessels of a vascularized tumor is described inU.S. Pat. No. 6,051,230, specifically incorporated herein by reference,and in U.S. Pat. No. 6,451,312, which particularly concerns geloninlinked to VEGF as a targeting agent.

As to ricin A chains, a further preferred toxin moiety is toxin A chainthat has been treated to modify or remove carbohydrate residues,so-called deglycosylated A chain (dgA). Deglycosylated ricin A chain ispreferred because of its extreme potency, longer half-life, and becauseit is economically feasible to manufacture it in a clinical grade andscale.

It may be desirable from a pharmacological standpoint to employ thesmallest molecule possible that nevertheless provides an appropriatebiological response. One may thus desire to employ smaller A chainpeptides that will provide an adequate anti-cellular response. To thisend, it has been discovered that ricin A chain may be “truncated” by theremoval of 30 N-terminal amino acids by Nagarase (Sigma), and stillretain an adequate toxin activity. It is proposed that where desired,this truncated A chain may be employed in conjugates in accordance withthe invention.

Alternatively, one may find that the application of recombinant DNAtechnology to the toxin A chain moiety will provide additional benefitsin accordance the invention. In that the cloning and expression ofbiologically active ricin A chain has been achieved, it is now possibleto identify and prepare smaller, or otherwise variant peptides, whichnevertheless exhibit an appropriate toxin activity. Moreover, the factthat ricin A chain has now been cloned allows the application ofsite-directed mutagenesis, through which one can readily prepare andscreen for A chain-derived peptides and obtain additional usefulmoieties for use in connection with the present invention.

F2. Cytokines

Cytokines and chemokines are particular examples of agents for linkingto the antibodies of the present invention. A range of cytokines may beused, including IL-3, IL-4, IL-5, IL-7, IL-8, IL-9, IL-11, IL-13, TGF-β,M-CSF, G-CSF, TNFβ, LAF, TCGF, BCGF, TRF, BAF, BDG, MP, LIF, OSM, TMF,IFN-α, IFN-β. More preferred cytokines include IL-1α, IL-1β, IL-2, IL-6,IL-10, GM-CSF, IFNγ, monocyte chemoattractant protein-1 (MCP-1),platelet-derived growth factor-BB (PDGF-BB) and C-reactive protein (CRP)and the like. Particularly preferred examples are TNFα, TNFα inducersand IL-12.

TNFα increases vascular permeability. This agent is contemplated forattachment to an antibody of the invention, particularly where theresultant immunoconjugate is used in combination therapy for thetreatment of cancer. The antibody will deliver the attached TNFα to thetumor environment, and the enhanced vascular permeability cause in thetumor will facilitate the penetration of a second anti-cancer agent intothe tumor, thus amplifying the overall anti-tumor effect, scFvconstructs are particularly contemplated for use in such embodiments.This is partly because TNFα functions as a trimer and the scFvconstructs will be able to trimerize readily.

IL-12, for example, may be attached to an antibody and used to redirecthost defenses to attack the tumor vessels. In using IL-12, an scFv formof antigen binding region may be preferred. The chemokine LEC(liver-expressed chemokine, also known as NCC-4, HCC-4, or LMC) isanother preferred component (Giovarelli et al., 2000). LEC ischemotactic for dendritic cells, monocytes, T cells, NK cells andneutrophils and can therefore improve host-mediated anti-tumorresponses.

F3. Coagulation Factors

An antibody against an anionic phospholipid, or a second generationantibody based upon the preferred 9D2 and 3G4 (ATCC 4545) antibodies ofthe invention, may be linked to a component that is capable of directlyor indirectly stimulating coagulation, to form a coaguligand. U.S. Pat.Nos. 6,093,399, 6,004,555, 5,877,289 and 6,036,955 are specificallyincorporated herein by reference for purposes of further describing theoperative association of coagulants with antibodies to formcoaguligands.

The antibodies of the invention may be directly linked to the coagulantor coagulation factor, or may be linked to a second binding region thatbinds and then releases the coagulant or coagulation factor. As usedherein, the terms “coagulant” and “coagulation factor” are each used torefer to a component that is capable of directly or indirectlystimulating coagulation under appropriate conditions, preferably whenprovided to a specific in vivo environment, such as the tumorvasculature.

Preferred coagulation factors are Tissue Factor compositions, such astruncated TF (tTF), dimeric, multimeric and mutant TF molecules.“Truncated TF” (tTF) refers to TF constructs that are renderedmembrane-binding deficient by removal of sufficient amino acid sequencesto effect this change in property. A “sufficient amount” in this contextis an amount of transmembrane amino acid sequence originally sufficientto enter the TF molecule in the membrane, or otherwise mediatefunctional membrane binding of the TF protein. The removal of such a“sufficient amount of transmembrane spanning sequence” therefore createsa truncated Tissue Factor protein or polypeptide deficient inphospholipid membrane binding capacity, such that the protein issubstantially a soluble protein that does not significantly bind tophospholipid membranes. Truncated TF thus substantially fails to convertFactor VII to Factor VIIa in a standard TF assay, and yet retainsso-called catalytic activity including activating Factor X in thepresence of Factor VIIa.

U.S. Pat. Nos. 5,504,067, 6,156,321, 6,132,729 and 6,132,730 arespecifically incorporated herein by reference for the purposes offurther describing such truncated Tissue Factor proteins. Preferably,the Tissue Factors for use in these aspects of the present inventionwill generally lack the transmembrane and cytosolic regions (amino acids220-263) of the protein. However, there is no need for the truncated TFmolecules to be limited to molecules of the exact length of 219 aminoacids.

Tissue Factor compositions may also be useful as dimers. Any of thetruncated, mutated or other Tissue Factor constructs may be prepared ina dimeric form for use in the present invention. As will be known tothose of ordinary skill in the art, such TF dimers may be prepared byemploying the standard techniques of molecular biology and recombinantexpression, in which two coding regions are prepared in-frame andexpressed from an expression vector. Equally, various chemicalconjugation technologies may be employed in connection with thepreparation of TF dimers. The individual TF monomers may be derivatizedprior to conjugation. All such techniques would be readily known tothose of skill in the art.

If desired, the Tissue Factor dimers or multimers may be joined via abiologically-releasable bond, such as a selectively-cleavable linker oramino acid sequence. For example, peptide linkers that include acleavage site for an enzyme preferentially located or active within atumor environment are contemplated. Exemplary forms of such peptidelinkers are those that are cleaved by urokinase, plasmin, thrombin,Factor IXa, Factor Xa, or a metalloproteinase, such as collagenase,gelatinase or stromelysin.

In certain embodiments, the Tissue Factor dimers may further comprise ahindered hydrophobic membrane insertion moiety, to later encourage thefunctional association of the Tissue Factor with the phospholipidmembrane, but only under certain defined conditions. As described in thecontext of the truncated Tissue Factors, hydrophobicmembrane-association sequences are generally stretches of amino acidsthat promote association with the phospholipid environment due to theirhydrophobic nature. Equally, fatty acids may be used to provide thepotential membrane insertion moiety.

Such membrane insertion sequences may be located either at theN-terminus or the C-terminus of the TF molecule, or generally appendedat any other point of the molecule so long as their attachment theretodoes not hinder the functional properties of the TF construct. Theintent of the hindered insertion moiety is that it remainsnon-functional until the TF construct localizes within the tumorenvironment, and allows the hydrophobic appendage to become accessibleand even further promote physical association with the membrane. Again,it is contemplated that biologically-releasable bonds andselectively-cleavable sequences will be particularly useful in thisregard, with the bond or sequence only being cleaved or otherwisemodified upon localization within the tumor environment and exposure toparticular enzymes or other bioactive molecules.

In other embodiments, the tTF constructs may be multimeric or polymeric.In this context a “polymeric construct” contains 3 or more Tissue Factorconstructs. A “multimeric or polymeric TF construct” is a construct thatcomprises a first TF molecule or derivative operatively attached to atleast a second and a third TF molecule or derivative. The multimers maycomprise between about 3 and about 20 such TF molecules. The individualTF units within the multimers or polymers may also be linked byselectively-cleavable peptide linkers or other biological-releasablebonds as desired. Again, as with the TF dimers discussed above, theconstructs may be readily made using either recombinant manipulation andexpression or using standard synthetic chemistry.

Even further TF constructs useful in context of the present inventionare those mutants deficient in the ability to activate Factor VII. Such“Factor VII activation mutants” are generally defined herein as TFmutants that bind functional Factor VII/VIIa, proteolytically activateFactor X, but are substantially free from the ability to proteolyticallyactivate Factor VII. Accordingly, such constructs are TF mutants thatlack Factor VII activation activity.

The ability of such Factor VII activation mutants to function inpromoting tumor-specific coagulation is based upon their specificdelivery to the tumor vasculature, and the presence of Factor VIIa atlow levels in plasma. Upon administration of such a Factor VIIactivation mutant conjugate, the mutant will be localized within thevasculature of a vascularized tumor. Prior to localization, the TFmutant would be generally unable to promote coagulation in any otherbody sites, on the basis of its inability to convert Factor VII toFactor VIIa. However, upon localization and accumulation within thetumor region, the mutant will then encounter sufficient Factor VIIa fromthe plasma in order to initiate the extrinsic coagulation pathway,leading to tumor-specific thrombosis. Exogenous Factor VIIa could alsobe administered to the patient.

Any one or more of a variety of Factor VII activation mutants may beprepared and used in connection with the present invention. There is asignificant amount of scientific knowledge concerning the recognitionsites on the TF molecule for Factor VII/VIIa. It will thus be understoodthat the Factor VII activation region generally lies between about aminoacid 157 and about amino acid 167 of the TF molecule. However, it iscontemplated that residues outside this region may also prove to berelevant to the Factor VII activating activity, and one may thereforeconsider introducing mutations into any one or more of the residuesgenerally located between about amino acid 106 and about amino acid 209of the TF sequence (WO 94/07515; WO 94/28017; each incorporated hereinby reference).

As detailed in U.S. Pat. Nos. 6,093,399, 6,004,555, 5,877,289 and6,036,955, a variety of other coagulation factors may be used inconnection with the present invention, as exemplified by the agents setforth below. Thrombin, Factor V/Va and derivatives, Factor VIII/VIIIaand derivatives, Factor IX/IXa and derivatives, Factor X/Xa andderivatives, Factor XI/XIa and derivatives, Factor XII/XIIa andderivatives, Factor XIII/XIIIa and derivatives, Factor X activator andFactor V activator may be used in the present invention.

Russell's viper venom Factor X activator is contemplated for use in thisinvention. Monoclonal antibodies specific for the Factor X activatorpresent in Russell's viper venom have also been produced, and could beused to specifically deliver the agent as part of a bispecific bindingligand.

Thromboxane A₂ is formed from endoperoxides by the sequential actions ofthe enzymes cyclooxygenase and thromboxane synthetase in plateletmicrosomes. Thromboxane A₂ is readily generated by platelets and is apotent vasoconstrictor, by virtue of its capacity to produce plateletaggregation. Both thromboxane A₂ and active analogues thereof arecontemplated for use in the present invention.

Thromboxane synthase, and other enzymes that synthesizeplatelet-activating prostaglandins, may also be used as “coagulants” inthe present context. Monoclonal antibodies to, and immunoaffinitypurification of, thromboxane synthase are known; as is the cDNA forhuman thromboxane synthase.

α2-antiplasmin, or α2-plasmin inhibitor, is a proteinase inhibitornaturally present in human plasma that functions to efficiently inhibitthe lysis of fibrin clots induced by plasminogen activator.α2-antiplasmin is a particularly potent inhibitor, and is contemplatedfor use in the present invention.

As the cDNA sequence for α2-antiplasmin is available, recombinantexpression and/or fusion proteins are preferred. Monoclonal antibodiesagainst α2-antiplasmin are also available that may be used in thebispecific binding ligand embodiments of the invention. These antibodiescould both be used to deliver exogenous α2-antiplasmin to the targetsite or to garner endogenous α2-antiplasmin and concentrate it withinthe targeted region.

F4. Anti-Tubulin Drugs

A range of drugs exert their effects via interfering with tubulinactivity. As tubulin functions are essential to mitosis and cellviability, certain “anti-tubulin drugs” are powerful chemotherapeuticagents. “Anti-tubulin drug(s)”, as used herein, means any agent, drug,prodrug or combination thereof that inhibits cell mitosis, preferably bydirectly or indirectly inhibiting tubulin activities necessary for cellmitosis, preferably tubulin polymerization or depolymerization.

Some of the more well known and currently preferred anti-tubulin drugsfor use with the present invention are colchicine; taxanes, such astaxol; vinca alkaloids, such as vinblastine, vincristine and vindescine;and combretastatins. Other suitable anti-tubulin drugs are cytochalasins(including B, J, E), dolastatin, auristatin PE, paclitaxel, ustiloxin D,rhizoxin, 1069C85, colcemid, albendazole, azatoxin and nocodazole.

As described in U.S. Pat. Nos. 5,892,069, 5,504,074 and 5,661,143, eachspecifically incorporated herein by reference, combretastatins areestradiol derivatives that generally inhibit cell mitosis. Exemplarycombretastatins that may be used in conjunction with the inventioninclude those based upon combretastatin A, B and/or D and thosedescribed in U.S. Pat. Nos. 5,892,069, 5,504,074 and 5,661,143.Combretastatins A-1, A-2, A-3, A-4, A-5, A-6, B-1, B-2, B-3 and B-4 areexemplary of the foregoing types.

U.S. Pat. Nos. 5,569,786 and 5,409,953, are incorporated herein byreference for purposes of describing the isolation, structuralcharacterization and synthesis of each of combretastatin A-1, A2, A-3,B-1, B-2, B-3 and B-4 and formulations and methods of using suchcombretastatins to treat neoplastic growth. Any one or more of suchcombretastatins may be used in conjunction with the present invention.

Combretastatin A-4, as described in U.S. Pat. Nos. 5,892,069, 5,504,074,5,661,143 and 4,996,237, each specifically incorporated herein byreference, may also be used herewith. U.S. Pat. No. 5,561,122 is furtherincorporated herein by reference for describing suitable combretastatinA-4 prodrugs, which are contemplated for combined use with the presentinvention.

U.S. Pat. No. 4,940,726, specifically incorporated herein by reference,particularly describes macrocyclic lactones denominated combretastatinD-1 and ‘Combretastatin D-2’, each of which may be used in combinationwith the compositions and methods of the present invention. U.S. Pat.No. 5,430,062, specifically incorporated herein by reference, concernsstilbene derivatives and combretastatin analogues with anti-canceractivity that may be used in combination with the present invention.

F5. Anti-Angiogenic Agents

Anti-angiogenic agents are useful for attachment to the antibodies andpeptides of the invention. Many anti-cancer agents have ananti-angiogenic effect as part of their mechanism of action. Any one ormore of such agents described for use in combination therapies,including those in Table E, may also be conjugated to an antibody of theinvention, as described herein. Certain other agents have beendiscovered, designed or selected to have an anti-angiogenic effect as aprimary mechanism of action. Examples of such agents are describedbelow, any of which may also be used to prepare an immunoconjugate orused separately in combination therapy with the invention.

Numerous tyrosine kinase inhibitors useful for the treatment ofangiogenesis, as manifest in various diseases states, are now known.These include, for example, the 4-aminopyrrolo[2,3-d]pyrimidines of U.S.Pat. No. 5,639,757, specifically incorporated herein by reference, whichmay also be used in combination with the present invention. Furtherexamples of organic molecules capable of modulating tyrosine kinasesignal transduction via the VEGFR2 receptor are the quinazolinecompounds and compositions of U.S. Pat. No. 5,792,771, which isspecifically incorporated herein by reference for the purpose ofdescribing further combinations for use with the present invention inthe treatment of angiogenic diseases.

Compounds of other chemical classes have also been shown to inhibitangiogenesis and may be used in combination with the present invention.For example, steroids such as the angiostatic 4,9(11)-steroids andC21-oxygenated steroids, as described in U.S. Pat. No. 5,972,922,specifically incorporated herein by reference, may be employed incombined therapy. U.S. Pat. Nos. 5,712,291 and 5,593,990, eachspecifically incorporated herein by reference, describe thalidomide andrelated compounds, precursors, analogs, metabolites and hydrolysisproducts, which may also be used in combination with the presentinvention to inhibit angiogenesis. The compounds in U.S. Pat. Nos.5,712,291 and 5,593,990 can be administered orally. Further exemplaryanti-angiogenic agents that are useful in connection with combinedtherapy are listed in Table B. Each of the agents listed therein areexemplary and by no means limiting.

TABLE B Inhibitors and Negative Regulators of Angiogenesis SubstancesReferences Angiostatin O'Reilly et al., 1994 Endostatin O'Reilly et al.,1997 16 kDa prolactin fragment Ferrara et al., 1991; Clapp et al., 1993;D'Angelo et al., 1995; Lee et al., 1998 Laminin peptides Kleinman etal., 1993; Yamamura et al., 1993; Iwamoto et al., 1996; Tryggvason, 1993Fibronectin peptides Grant et al., 1998; Sheu et al., 1997 Tissuemetalloproteinase Sang, 1998 inhibitors (TIMP 1, 2, 3, 4) Plasminogenactivator Soff et al., 1995 inhibitors (PAI-1, -2) Tumor necrosis factorα Frater-Schroder et al., 1987 (high dose, in vitro) TGF-β1 RayChadhuryand D'Amore, 1991; Tada et al., 1994 Interferons (IFN-α, -β, γ) Moore etal., 1998; Lingen et al., 1998 ELR- CXC Chemokines: IL-12; Moore et al.,1998; Hiscox and Jiang, 1997; SDF-1; MIG; Platelet factor Coughlin etal., 1998; Tanaka et al., 1997 4 (PF-4); IP-10 Thrombospondin (TSP) Goodet al., 1990; Frazier, 1991; Bornstein, 1992; Tolsma et al., 1993;Sheibani and Frazier, 1995; Volpert et al., 1998 SPARC Hasselaar andSage, 1992; Lane et al., 1992; Jendraschak and Sage, 19962-Methoxyoestradiol Fotsis et al., 1994 Proliferin-related proteinJackson et al., 1994 Suramin Gagliardi et al., 1992; Takano et al.,1994; Waltenberger et al., 1996; Gagliardi et al., 1998; Manetti et al.,1998 Thalidomide D'Amato et al., 1994; Kenyon et al., 1997 Wells, 1998Cortisone Thorpe et al., 1993 Folkman et al., 1983 Sakamoto et al., 1986Linomide Vukanovic et al., 1993; Ziche et al., 1998; Nagler et al., 1998Fumagillin (AGM-1470; TNP-470) Sipos et al., 1994; Yoshida et al., 1998Tamoxifen Gagliardi and Collins, 1993; Linder and Borden, 1997; Haran etal., 1994 Korean mistletoe extract Yoon et al., 1995 (Viscum albumcoloratum) Retinoids Oikawa et al., 1989; Lingen et al., 1996; Majewskiet al. 1996 CM101 Hellerqvist et al., 1993; Quinn et al., 1995; Wamil etal., 1997; DeVore et al., 1997 Dexamethasone Hori et al., 1996; Wolff etal., 1997 Leukemia inhibitory factor (LIF) Pepper et al., 1995

Certain preferred components for use in inhibiting angiogenesis areangiostatin, endostatin, vasculostatin, canstatin and maspin. Theprotein named “angiostatin” is disclosed in U.S. Pat. Nos. 5,776,704;5,639,725 and 5,733,876, each incorporated herein by reference.Angiostatin is a protein having a molecular weight of between about 38kD and about 45 kD, as determined by reducing polyacrylamide gelelectrophoresis, which contains approximately Kringle regions 1 through4 of a plasminogen molecule. Angiostatin generally has an amino acidsequence substantially similar to that of a fragment of murineplasminogen beginning at amino acid number 98 of an intact murineplasminogen molecule.

The amino acid sequence of angiostatin varies slightly between species.For example, in human angiostatin, the amino acid sequence issubstantially similar to the sequence of the above described murineplasminogen fragment, although an active human angiostatin sequence maystart at either amino acid number 97 or 99 of an intact humanplasminogen amino acid sequence. Further, human plasminogen may be used,as it has similar anti-angiogenic activity, as shown in a mouse tumormodel.

Certain anti-angiogenic therapies have already been shown to cause tumorregressions, and angiostatin is one such agent. Endostatin, a 20 kDaCOOH-terminal fragment of collagen XVIII, the bacterial polysaccharideCM101, and the antibody LM609 also have angiostatic activity. However,in light of their other properties, they are referred to asanti-vascular therapies or tumor vessel toxins, as they not only inhibitangiogenesis but also initiate the destruction of tumor vessels throughmostly undefined mechanisms.

Angiostatin and endostatin have become the focus of intense study, asthey are the first angiogenesis inhibitors that have demonstrated theability to not only inhibit tumor growth but also cause tumorregressions in mice. There are multiple proteases that have been shownto produce angiostatin from plasminogen including elastase, macrophagemetalloelastase (MME), matrilysin (MMP-7), and 92 kDa gelatinase B/typeIV collagenase (MMP-9).

MME can produce angiostatin from plasminogen in tumors andgranulocyte-macrophage colony-stimulating factor (GMCSF) upregulates theexpression of MME by macrophages inducing the production of angiostatin.The role of MME in angiostatin generation is supported by the findingthat MME is in fact expressed in clinical samples of hepatocellularcarcinomas from patients. Another protease thought to be capable ofproducing angiostatin is stromelysin-1 (MMP-3). MMP-3 has been shown toproduce angiostatin-like fragments from plasminogen in vitro. Themechanism of action for angiostatin is currently unclear, it ishypothesized that it binds to an unidentified cell surface receptor onendothelial cells inducing endothelial cell to undergo programmed celldeath or mitotic arrest.

Endostatin appears to be an even more powerful anti-angiogenesis andanti-tumor agent although its biology is less clear. Endostatin iseffective at causing regressions in a number of tumor models in mice.Tumors do not develop resistance to endostatin and, after multiplecycles of treatment, tumors enter a dormant state during which they donot increase in volume. In this dormant state, the percentage of tumorcells undergoing apoptosis was increased, yielding a population thatessentially stays the same size. Endostatin is thought to bind anunidentified endothelial cell surface receptor that mediates its effect.

U.S. Pat. No. 5,854,205, to Folkman and O'Reilly, specificallyincorporated herein by reference, concerns endostatin and its use as aninhibitor of endothelial cell proliferation and angiogenesis. Theendostatin protein corresponds to a C-terminal fragment of collagen typeXVIII, and the protein can be isolated from a variety of sources. U.S.Pat. No. 5,854,205 also teaches that endostatin can have an amino acidsequence of a fragment of collagen type XVIII, a collasen type XV, orBOVMPE 1 pregastric esterase. Combinations of endostatin with otheranti-angiogenic proteins, particularly angiostatin, are also describedby U.S. Pat. No. 5,854,205, such that the combined compositions arecapable of effectively regressing the mass of an angiogenesis-dependenttumor.

CM101 is a bacterial polysaccharide that has been well characterized inits ability to induce neovascular inflammation in tumors. CM101 binds toand cross-links receptors expressed on dedifferentiated endothelium thatstimulates the activation of the complement system. It also initiates acytokine-driven inflammatory response that selectively targets thetumor. It is a uniquely antipathoangiogenic agent that downregulates theexpression VEGF and its receptors. CM101 is currently in clinical trialsas an anti-cancer drug, and can be used in combination with thisinvention.

Thrombospondin (TSP-1) and platelet factor 4 (PF4) may also be used inthe present invention. These are both angiogenesis inhibitors thatassociate with heparin and are found in platelet α-granules. TSP-1 is alarge 450 kDa multi-domain glycoprotein that is constituent of theextracellular matrix. TSP-1 binds to many of the proteoglycan moleculesfound in the extracellular matrix including, HSPGs, fibronectin,laminin, and different types of collagen. TSP-1 inhibits endothelialcell migration and proliferation in vitro and angiogenesis in vivo.TSP-1 can also suppress the malignant phenotype and tumorigenesis oftransformed endothelial cells. The tumor suppressor gene p53 has beenshown to directly regulate the expression of TSP-1 such that, loss ofp53 activity causes a dramatic reduction in TSP-1 production and aconcomitant increase in tumor initiated angiogenesis.

PF4 is a 70aa protein that is member of the CXC ELR-family of chemokinesthat is able to potently inhibit endothelial cell proliferation in vitroand angiogenesis in vivo. PF4 administered intratumorally or deliveredby an adenoviral vector is able to cause an inhibition of tumor growth.

Interferons and metalloproteinase inhibitors are two other classes ofnaturally occurring angiogenic inhibitors that can be deliveredaccording to the present invention. The anti-endothelial activity of theinterferons has been known since the early 1980s, however, the mechanismof inhibition is still unclear. It is known that they can inhibitendothelial cell migration and that they do have some anti-angiogenicactivity in vivo that is possibly mediated by an ability to inhibit theproduction of angiogenic promoters by tumor cells. Vascular tumors inparticular are sensitive to interferon, for example, proliferatinghemangiomas can be successfully treated with IFNα.

Tissue inhibitors of metalloproteinases (TIMPs) are a family ofnaturally occurring inhibitors of matrix metalloproteases (MMPs) thatcan also inhibit angiogenesis and can be used in the treatment protocolsof the present invention. MMPs play a key role in the angiogenic processas they degrade the matrix through which endothelial cells andfibroblasts migrate when extending or remodeling the vascular network.In fact, one member of the MMPs, MMP-2, has been shown to associate withactivated endothelium through the integrin αvβ3 presumably for thispurpose. If this interaction is disrupted by a fragment of MMP-2, thenangiogenesis is downregulated and in tumors growth is inhibited.

There are a number of pharmacological agents that inhibit angiogenesis,any one or more of which may be used as part of the present invention.These include AGM-1470/TNP-470, thalidomide, and carboxyamidotriazole(CAI). Fumagillin was found to be a potent inhibitor of angiogenesis in1990, and since then the synthetic analogues of fumagillin, AGM-1470 andTNP-470 have been developed. Both of these drugs inhibit endothelialcell proliferation in vitro and angiogenesis in vivo. TNP-470 has beenstudied extensively in human clinical trials with data suggesting thatlong-term administration is optimal.

Thalidomide was originally used as a sedative but was found to be apotent teratogen and was discontinued. In 1994 it was found thatthalidomide is an angiogenesis inhibitor. Thalidomide is currently inclinical trials as an anti-cancer agent as well as a treatment ofvascular eye diseases.

CAI is a small molecular weight synthetic inhibitor of angiogenesis thatacts as a calcium channel blocker that prevents actin reorganization,endothelial cell migration and spreading on collagen IV. CAI inhibitsneovascularization at physiological attainable concentrations and iswell tolerated orally by cancer patients. Clinical trials with CAI haveyielded disease stabilization in 49% of cancer patients havingprogressive disease before treatment.

Cortisone in the presence of heparin or heparin fragments was shown toinhibit tumor growth in mice by blocking endothelial cell proliferation.The mechanism involved in the additive inhibitory effect of the steroidand heparin is unclear although it is thought that the heparin mayincrease the uptake of the steroid by endothelial cells. The mixture hasbeen shown to increase the dissolution of the basement membraneunderneath newly formed capillaries and this is also a possibleexplanation for the additive angiostatic effect. Heparin-cortisolconjugates also have potent angiostatic and anti-tumor effects activityin vivo.

Further specific angiogenesis inhibitors may be delivered to tumorsusing the tumor targeting methods of the present invention. Theseinclude, but are not limited to, Anti-Invasive Factor, retinoic acidsand paclitaxel (U.S. Pat. No. 5,716,981; incorporated herein byreference); AGM-1470 (Ingber et al., 1990; incorporated herein byreference); shark cartilage extract (U.S. Pat. No. 5,618,925;incorporated herein by reference); anionic polyamide or polyureaoligomers (U.S. Pat. No. 5,593,664; incorporated herein by reference);oxindole derivatives (U.S. Pat. No. 5,576,330; incorporated herein byreference); estradiol derivatives (U.S. Pat. No. 5,504,074; incorporatedherein by reference); and thiazolopyrimidine derivatives (U.S. Pat. No.5,599,813; incorporated herein by reference) are also contemplated foruse as anti-angiogenic compositions for the combined uses of the presentinvention.

Compositions comprising an antagonist of an α_(v)β₃ integrin may also beused to inhibit angiogenesis as part of the present invention. Asdisclosed in U.S. Pat. No. 5,766,591 (incorporated herein by reference),RGD-containing polypeptides and salts thereof, including cyclicpolypeptides, are suitable examples of α_(v)β₃ integrin antagonists.

As angiopoietins are ligands for Tie2, other methods of therapeuticintervention based upon altering signaling through the Tie2 receptor canalso be used in combination herewith. For example, a soluble Tie2receptor capable of blocking Tie2 activation (Lin et al., 1998a) can beemployed. Delivery of such a construct using recombinant adenoviral genetherapy has been shown to be effective in treating cancer and reducingmetastases (Lin et al., 1998a).

The angiopoietins, in common with the members of the VEGF family, aregrowth factors specific for vascular endothelium (Davis and Yancopoulos,1999; Holash et al., 1999; incorporated herein by reference). Theangiopoietins first described were a naturally occurring receptoractivator or agonist, angiopoietin-1 (Ang-1), and a naturally occurringreceptor antagonist, angiopoietin-2 (Ang-2), both of which act by meansof the endothelial cell tyrosine kinase receptor, Tie2.

Two new angiopoietins, angiopoietin-3 (mouse) and angiopoietin-4 (human)have also been identified (Valenzuela et al., 1999). Angiopoietin-3appears to act as an antagonist (like Ang-2), whereas angiopoietin-4appears to function as an agonist (like Ang-1) (Valenzuela et al.,1999). A protein termed angiopoietin-3 was also cloned from human heartand reported not to have mitogenic effects on endothelial cells (Kim etal., 1999).

Whereas VEGF is necessary for the early stages of vascular development,angiopoietin-1 is generally required for the later stages ofvascularization. VEGF thus acts to promote endothelial celldifferentiation, proliferation and primitive vessel formation.Angiopoietin-1 acts, via the Tie2 receptor, to promote maintenance andstabilization of mature vessels. Angiopoietin-1 is thus a maturation orstabilization factor, thought to convert immature vessels to immaturevessels by promoting interactions between endothelial cells andsurrounding support cells (Holash et al., 1999).

F6. Apoptosis-Inducing Agents

The present invention may also be used to deliver agents that induceapoptosis in any cells within the tumor, including tumor cells and tumorvascular endothelial cells. Many anti-cancer agents have, as part oftheir mechanism of action, an apoptosis-inducing effect. Any one or moreof such agents described for use in combination therapies, includingthose in Table F, may also be conjugated to an antibody of theinvention, as described herein. Certain other agents have beendiscovered, designed or selected to have an apoptosis-inducing effect asa primary mechanism. Examples of such agents are described below, any ofwhich may also be used to prepare an immunoconjugate or used separatelyin combination therapy with the invention.

Many forms of cancer have reports of mutations in tumor suppressorgenes, such as p53. Inactivation of p53 results in a failure to promoteapoptosis. With this failure, cancer cells progress in tumorigenesis,rather than become destined for cell death. Thus, delivery of tumorsuppressors is also contemplated for use in the present invention tostimulate cell death. Exemplary tumor suppressors include, but are notlimited to, p53, Retinoblastoma gene (Rb), Wilm's tumor (WT1), baxalpha, interleukin-1b-converting enzyme and family, MEN-1 gene,neurofibromatosis, type 1 (NF1), cdk inhibitor p16, colorectal cancergene (DCC), familial adenomatosis polyposis gene (FAP), multiple tumorsuppressor gene (MTS-1), BRCA1 and BRCA2.

Preferred for use are the p53 (U.S. Pat. Nos. 5,747,469; 5,677,178; and5,756,455; each incorporated herein by reference), Retinoblastoma, BRCA1(U.S. Pat. Nos. 5,750,400; 5,654,155; 5,710,001; 5,756,294; 5,709,999;5,693,473; 5,753,441; 5,622,829; and 5,747,282; each incorporated hereinby reference), MEN-1 (GenBank accession number U93236) and adenovirusE1A (U.S. Pat. No. 5,776,743; incorporated herein by reference) genes.

Other oncogenes that inhibit apoptosis or programmed cell death include,but are not limited to, bcr-abl, bcl-2 (distinct from bcl-1, cyclin D1;GenBank accession numbers M 14745, X06487; U.S. Pat. Nos. 5,650,491; and5,539,094; each incorporated herein by reference) and family membersincluding Bcl-xl, Mcl-1, Bak, A1, A20. Overexpression of bcl-2 was firstdiscovered in T cell lymphomas, bcl-2 functions as an oncogene bybinding and inactivating Bax, a protein in the apoptotic pathway.Inhibition of bcl-2 function prevents inactivation of Bax, and allowsthe apoptotic pathway to proceed. Thus, inhibition of this class ofoncogenes, e.g., using antisense nucleotide sequences, is contemplatedfor use in the present invention in aspects wherein enhancement ofapoptosis is desired (U.S. Pat. Nos. 5,650,491; 5,539,094; and5,583,034; each incorporated herein by reference).

Other compositions that may be delivered by the antibodies of thepresent invention include genes encoding the tumor necrosis factorrelated apoptosis inducing ligand termed TRAIL, and the TRAILpolypeptide (U.S. Pat. No. 5,763,223; incorporated herein by reference);the 24 kD apoptosis-associated protease of U.S. Pat. No. 5,605,826(incorporated herein by reference); Fas-associated factor 1, FAF1 (U.S.Pat. No. 5,750,653; incorporated herein by reference). Also contemplatedfor use in these aspects of the present invention is the provision ofinterleukin-1β-converting enzyme and family members, which are alsoreported to stimulate apoptosis.

Compounds such as carbostyril derivatives (U.S. Pat. Nos. 5,672,603; and5,464,833; each incorporated herein by reference); branched apogenicpeptides (U.S. Pat. No. 5,591,717; incorporated herein by reference);phosphotyrosine inhibitors and non-hydrolyzable phosphotyrosine analogs(U.S. Pat. Nos. 5,565,491; and 5,693,627; each incorporated herein byreference); agonists of RXR retinoid receptors (U.S. Pat. No. 5,399,586;incorporated herein by reference); and even antioxidants (U.S. Pat. No.5,571,523; incorporated herein by reference) may also be used. Tyrosinekinase inhibitors, such as genistein, may also be linked to theantibodies of the present invention (as supported by U.S. Pat. No.5,587,459; incorporated herein by reference).

F7. Anti-Viral Agents

As anionic phospholipids and aminophospholipids, particularly PS and PE,become exposed on virally infected cells, the antibodies of theinvention, such as the 9D2 and 3G4 (ATCC 4545) antibodies, may also belinked to any one or more anti-viral agents. Additional reasonsunderlying these aspects of the invention, and the advantages thereof,are described in more detail below in regard to the PE-binding peptide,anti-viral conjugates.

Exemplary anti-viral agents are for linking to antibodies or peptidesare also described in more detail in connection with the PE-bindingpeptide, anti-viral conjugates of the invention. Any one or moreanti-viral agents, including those in Table G, may be conjugated to anantibody of the invention, as described herein. Such anti-viral agentsmay also be used separately in the combination anti-viral therapies ofthe invention.

G. Biologically Functional Equivalents

Equivalents, or even improvements, of antibodies and effectors can nowbe made, generally using the materials provided above as a startingpoint. Modifications and changes may be made in the structure of such anantibody and still obtain a molecule having like or otherwise desirablecharacteristics. For example, certain amino acids may substituted forother amino acids in a protein structure without appreciable loss ofinteractive binding capacity. These considerations also apply to toxins,anti-angiogenic agents, apoptosis-inducing agents, coagulants and thelike.

Since it is the interactive capacity and nature of a protein thatdefines that protein's biological functional activity, certain aminoacid sequence substitutions can be made in a protein sequence (or ofcourse, the underlying DNA sequence) and nevertheless obtain a proteinwith like (agonistic) properties. It is thus contemplated that variouschanges may be made in the sequence of the antibodies or therapeuticagents (or underlying DNA sequences) without appreciable loss of theirbiological utility or activity. Biological functional equivalents madefrom mutating an underlying DNA sequence can be made using the codoninformation provided herein in Table A, and the supporting technicaldetails on site-specific mutagenesis.

It also is well understood by the skilled artisan that, inherent in thedefinition of a “biologically functional equivalent” protein or peptide,is the concept that there is a limit to the number of changes that maybe made within a defined portion of the molecule and still result in amolecule with an acceptable level of equivalent biological activity.Biologically functional equivalent proteins and peptides are thusdefined herein as those proteins and peptides in which certain, not mostor all, of the amino acids may be substituted. Of course, a plurality ofdistinct proteins/peptides with different substitutions may easily bemade and used in accordance with the invention.

Amino acid substitutions are generally based on the relative similarityof the amino acid side-chain substituents, for example, theirhydrophobicity, hydrophilicity, charge, size, and the like. An analysisof the size, shape and type of the amino acid side-chain substituentsreveals that arginine, lysine and histidine are all positively chargedresidues; that alanine, glycine and serine are all a similar size; andthat phenylalanine, tryptophan and tyrosine all have a generally similarshape. Therefore, based upon these considerations, arginine, lysine andhistidine; alanine, glycine and serine; and phenylalanine, tryptophanand tyrosine; are defined herein as biologically functional equivalents.

In making more quantitative changes, the hydropathic index of aminoacids may be considered. Each amino acid has been assigned a hydropathicindex on the basis of their hydrophobicity and charge characteristics,these are: isoleucine (+4.5); valine (+4.2); leucine (+3.8);phenylalanine (+2.8); cysteine/cystine (+2.5); methionine (+1.9);alanine (+1.8); glycine (−0.4); threonine (−0.7); serine (−0.8);tryptophan (−0.9); tyrosine (−1.3); proline (−1.6); histidine (−3.2);glutamate (−3.5); glutamine (−3.5); aspartate (−3.5); asparagine (−3.5);lysine (−3.9); and arginine (−4.5).

The importance of the hydropathic amino acid index in conferringinteractive biological function on a protein is generally understood inthe art (Kyte and Doolittle, 1982, incorporated herein by reference). Itis known that certain amino acids may be substituted for other aminoacids having a similar hydropathic index or score and still retain asimilar biological activity. In making changes based upon thehydropathic index, the substitution of amino acids whose hydropathicindices are within ±2 is preferred, those which are within ±1 areparticularly preferred, and those within ±0.5 are even more particularlypreferred.

It is thus understood that an amino acid can be substituted for anotherhaving a similar hydrophilicity value and still obtain a biologicallyequivalent protein. As detailed in U.S. Pat. No. 4,554,101 (incorporatedherein by reference), the following hydrophilicity values have beenassigned to amino acid residues: arginine (+3.0); lysine (+3.0);aspartate (+3.0±1); glutamate (+3.0±1); serine (+0.3); asparagine(+0.2); glutamine (+0.2); glycine (0); threonine (−0.4); proline(−0.5±1); alanine (−0.5); histidine (−0.5); cysteine (−1.0); methionine(−1.3); valine (−1.5); leucine (−1.8); isoleucine (−1.8); tyrosine(−2.3); phenylalanine (−2.5); tryptophan (−3.4).

In making changes based upon hydrophilicity values, the substitution ofamino acids whose hydrophilicity values are within ±2 is preferred,those which are within ±1 are particularly preferred, and those within±0.5 are even more particularly preferred.

H. Conjugation

Antibodies to aminophospholipids and anionic phospholipids, includingselected anti-PS antibodies with improved properties, such as 9D2 and3G4 (ATCC 4545), may be conjugated or attached to, or operativelyassociated with, anti-cellular and cytotoxic agents to prepare“immunotoxins”; to coagulants, either directly or indirectly, to prepare“coaguligands”; or to anti-viral agents, such as nucleosides, to prepareanti-viral immunoconjugates or “immunovirocides”. PE-binding peptidessuch as duramycin may also be conjugated or attached to, or operativelyassociated with, inert carriers, targeting agents or anti-viral agents,to prepare a range of PE-binding peptide derivatives and anti-viralpeptide conjugates.

Although covalent linkages are preferred, other means of operativeattachment may also be used. For example, linked constructs may begenerated using avidin:biotin bridges. In addition to the knowledgeavailable to those of ordinary skill in the art, co-owned U.S. Pat. No.6,093,399 is specifically incorporated herein by reference for purposesof even further describing and enabling the use of avidin:biotin in theoperative attachment of antibodies and targeting agents to biologicaland therapeutic agents.

The two agents may also be joined by a second binding region, preferablyan antibody or antigen binding region thereof. This is exemplified bycoaguligands wherein the targeting agent is linked to the coagulant viaa second binding region (U.S. Pat. Nos. 6,093,399, 6,004,555, 5,877,289,and 6,036,955, each specifically incorporated herein by reference),which have been made and used successfully in the treatment of cancer.Where the first targeting agent is an antibody or antigen bindingregion, the use of a second binding region that is also an antibody, orantigen binding region, results in a bispecific antibody construct. Thepreparation and use of bispecific antibodies in general is well known inthe art, and is further disclosed herein.

Immunoconjugate technology is now generally known in the art. However,certain advantages may be achieved through the application of certainpreferred technology, both in the preparation and purification forsubsequent clinical administration. For example, while IgG basedconstructs will typically exhibit better binding capability and slowerblood clearance than their Fab′ counterparts, Fab′ fragment-basedconstructs will generally exhibit better tissue penetrating capability.

Additionally, while numerous types of disulfide-bond containing linkersare known that can be successfully employed in antibody and peptideconjugation, certain linkers will generally be preferred over otherlinkers, based on differing pharmacological characteristics andcapabilities. For example, linkers that contain a disulfide bond that issterically “hindered” are to be preferred, due to their greaterstability in vivo, thus preventing release of the coagulant prior tobinding at the site of action.

Each type of cross-linker, as well as how the cross-linking isperformed, will tend to vary the pharmacodynamics of the resultantconjugate. One may desire to have a conjugate that will remain intactunder conditions found everywhere in the body except the intended siteof action, at which point it is desirable that the conjugate have good“release” characteristics. Therefore, the particular cross-linkingscheme, including in particular the particular cross-linking reagentused and the structures that are cross-linked, will be of somesignificance.

Depending on the specific agents to be conjugated, it may be necessaryor desirable to provide a peptide spacer operatively attaching theantibody or PE-binding peptide and the second or therapeutic agent.Certain peptide spacers are capable of folding into a disulfide-bondedloop structure. Proteolytic cleavage within the loop would then yield aheterodimeric polypeptide wherein the antibody and the therapeutic agentare linked by only a single disulfide bond. An example of such a toxinis a Ricin A-chain toxin.

When certain other toxin compounds are utilized, a non-cleavable peptidespacer may be provided to operatively attach the antibody and the toxincompound of the fusion protein. Toxins which may be used in conjunctionwith non-cleavable peptide spacers are those which may, themselves, beconverted by proteolytic cleavage, into a cytotoxic disulfide-bondedform. An example of such a toxin compound is a Pseudonomas exotoxincompound.

A variety of chemotherapeutic and other pharmacological agents have nowbeen successfully conjugated to antibodies and shown to functionpharmacologically. Exemplary antineoplastic agents that have beeninvestigated include doxorubicin, daunomycin, methotrexate, vinblastine,and various others. Moreover, the attachment of other agents such asneocarzinostatin, macromycin, trenimon and α-amanitin has beendescribed. These attachment methods can be adapted for use herewith.

Any covalent linkage to the antibody or PE-binding peptide shouldideally be made at a site distinct from the functional site(s). Thecompositions are thus “linked” in any operative manner that allows eachregion to perform its intended function without significant impairment,in particular, so that the resultant construct still binds to theintended antigen or to PE and so that the attached agent substantiallymaintains biological activity and/or recovers biological activity whenreleased from the construct.

Attachment of biological agents via the carbohydrate moieties onantibodies is also contemplated. Glycosylation, both O-linked andN-linked, naturally occurs in antibodies. Recombinant antibodies can bemodified to recreate or create additional glycosylation sites ifdesired, which is simply achieved by engineering the appropriate aminoacid sequences (such as Asn-X-Ser, Asn-X-Thr, Ser, or Thr) into theprimary sequence of the antibody.

H1. Biochemical Cross-Linkers

In additional to the general information provided above, antibodies orPE-binding peptides may be conjugated to therapeutic or other agentsusing certain preferred biochemical cross-linkers. Cross-linkingreagents are used to form molecular bridges that tie together functionalgroups of two different molecules. To link two different proteins in astep-wise manner, hetero-bifunctional cross-linkers can be used thateliminate unwanted homopolymer formation. Exemplary hetero-bifunctionalcross-linkers are referenced in Table C.

TABLE C HETERO-BIFUNCTIONAL CROSS-LINKERS Spacer Arm Length LinkerReactive Toward Advantages and Applications after cross-linking SMPTPrimary amines Greater stability 11.2 A Sulfhydryls SPDP Primary aminesThiolation  6.8 A Sulfhydryls Cleavable cross-linking LC-SPDP Primaryamines Extended spacer arm 15.6 A Sulfhydryls Sulfo-LC-SPDP Primaryamines Extended spacer arm 15.6 A Sulfhydryls Water-soluble SMCC Primaryamines Stable maleimide reactive group 11.6 A SulfhydrylsEnzyme-antibody conjugation Hapten-carrier protein conjugationSulfo-SMCC Primary amines Stable maleimide reactive group 11.6 ASulfhydryls Water-soluble Enzyme-antibody conjugation MBS Primary aminesEnzyme-antibody conjugation  9.9 A Sulfhydryls Hapten-carrier proteinconjugation Sulfo-MBS Primary amines Water-soluble  9.9 A SulfhydrylsSIAB Primary amines Enzyme-antibody conjugation 10.6 A SulfhydrylsSulfo-SIAB Primary amines Water-soluble 10.6 A Sulfhydryls SMPB Primaryamines Extended spacer arm 14.5 A Sulfhydryls Enzyme-antibodyconjugation Sulfo-SMPB Primary amines Extended spacer arm 14.5 ASulfhydryls Water-soluble EDC/Sulfo-NHS Primary amines Hapten-Carrierconjugation  0 Carboxyl groups ABH Carbohydrates Reacts with sugargroups 11.9 A Nonselective

Hetero-bifunctional cross-linkers contain two reactive groups: onegenerally reacting with primary amine group (e.g., N-hydroxysuccinimide) and the other generally reacting with a thiol group (e.g.,pyridyl disulfide, maleimides, halogens, etc.). Through the primaryamine reactive group, the cross-linker may react with the lysineresidue(s) of one protein (e.g., the selected antibody, fragment orPE-binding peptide) and through the thiol reactive group, thecross-linker, already tied up to the first protein, reacts with thecysteine residue (free sulfhydryl group) of the other protein.

Compositions therefore generally have, or are derivatized to have, afunctional group available for cross-linking purposes. This requirementis not considered to be limiting in that a wide variety of groups can beused in this manner. For example, primary or secondary amine groups,hydrazide or hydrazine groups, carboxyl alcohol, phosphate, carbamate,or alkylating groups may be used for binding or cross-linking.

The spacer arm between the two reactive groups of a cross-linkers mayhave various length and chemical compositions. A longer spacer armallows a better flexibility of the conjugate components while someparticular components in the bridge (e.g., benzene group) may lend extrastability to the reactive group or an increased resistance of thechemical link to the action of various aspects (e.g., disulfide bondresistant to reducing agents). The use of peptide spacers, such asL-Leu-L-Ala-L-Leu-L-Ala, is also contemplated.

It is preferred that a cross-linker having reasonable stability in bloodwill be employed. Numerous types of disulfide-bond containing linkersare known that can be successfully employed in conjugation. Linkers thatcontain a disulfide bond that is sterically hindered may prove to givegreater stability in vivo, preventing release of the agent prior tobinding at the site of action. These linkers are thus one preferredgroup of linking agents.

One of the most preferred cross-linking reagents is SMPT, which is abifunctional cross-linker containing a disulfide bond that is“sterically hindered” by an adjacent benzene ring and methyl groups. Itis believed that steric hindrance of the disulfide bond serves afunction of protecting the bond from attack by thiolate anions such asglutathione which can be present in tissues and blood, and thereby helpin preventing decoupling of the conjugate prior to the delivery of theattached agent to the tumor site. It is contemplated that the SMPT agentmay also be used in connection with the conjugates of this invention.

The SMPT cross-linking reagent, as with many other known cross-linkingreagents, lends the ability to cross-link functional groups such as theSH of cysteine or primary amines (e.g., the epsilon amino group oflysine). Another possible type of cross-linker includes thehetero-bifunctional photoreactive phenylazides containing a cleavabledisulfide bond such as sulfosuccinimidyl-2-(p-azido salicylamido)ethyl-1,3′-dithiopropionate. The N-hydroxy-succinimidyl group reactswith primary amino groups and the phenylazide (upon photolysis) reactsnon-selectively with any amino acid residue.

In addition to hindered cross-linkers, non-hindered linkers can also beemployed in accordance herewith. Other useful cross-linkers, notconsidered to contain or generate a protected disulfide, include SATA,SPDP and 2-iminothiolane. The use of such cross-linkers is wellunderstood in the art.

Once conjugated, the conjugate is separated from unconjugated antibodiesor peptides and other agents and from other contaminants. A large anumber of purification techniques are available for use in providingconjugates of a sufficient degree of purity to render them clinicallyuseful. Purification methods based upon size separation, such as gelfiltration, gel permeation or high performance liquid chromatography,will generally be of most use. Other chromatographic techniques, such asBlue-Sepharose separation, may also be used.

H2. Biologically Releasable Linkers

Although it is preferred that any linking moiety will have reasonablestability in blood, to prevent substantial release of the attachedtherapeutic agent before targeting to the disease, e.g., tumor site, incertain aspects, the use of biologically-releasable bonds and/orselectively cleavable spacers or linkers is contemplated.“Biologically-releasable bonds” and “selectively cleavable spacers orlinkers” still have reasonable stability in the circulation.

The antibodies or PE-binding peptides in accordance with the inventionmay thus be linked to one or more therapeutic or second agents via abiologically-releasable bond. Any form of targeting agent or antibodymay be employed, including intact antibodies, although ScFv fragmentswill be preferred in certain embodiments.

“Biologically-releasable bonds” or “selectively hydrolyzable bonds”include all linkages that are releasable, cleavable or hydrolyzable onlyor preferentially under certain conditions. This includes disulfide andtrisulfide bonds and acid-labile bonds, as described in U.S. Pat. Nos.5,474,765 and 5,762,918, each specifically incorporated herein byreference.

The use of an acid sensitive spacer for attachment of a therapeuticagent to an antibody or PE-binding peptide of the invention isparticularly contemplated. In such embodiments, the therapeutic agentsare released within the acidic compartments inside a cell. It iscontemplated that acid-sensitive release may occur extracellularly, butstill after specific targeting, preferably to the tumor site or virallyinfected cell. Certain currently preferred examples include antibodieslinked to colchicine or doxorubicin via an acid sensitive spacer.Attachment via carbohydrate moieties of antibodies is also contemplated.In such embodiments, the therapeutic agent are released within theacidic compartments inside a cell.

The antibody or PE-binding peptide may also be derivatized to introducefunctional groups permitting the attachment of the therapeutic agentsthrough a biologically releasable bond. The antibody or PE-bindingpeptide may thus be derivatized to introduce side chains terminating inhydrazide, hydrazine, primary amine or secondary amine groups.Therapeutic agents may be conjugated through a Schiff's base linkage, ahydrazone or acyl hydrazone bond or a hydrazide linker (U.S. Pat. Nos.5,474,765 and 5,762,918, each specifically incorporated herein byreference).

Also as described in U.S. Pat. Nos. 5,474,765 and 5,762,918, eachspecifically incorporated herein by reference, the antibody orPE-binding peptide may be operatively attached to the therapeutic agentthrough one or more biologically releasable bonds that areenzyme-sensitive bonds, including peptide bonds, esters, amides,phosphodiesters and glycosides.

Certain preferred aspects of the invention concern the use of peptidelinkers that include at least a first cleavage site for a peptidaseand/or proteinase that is preferentially located within a disease site,particularly within the tumor environment. The antibody- orpeptide-mediated delivery of the attached therapeutic agent thus resultsin cleavage specifically within the disease site or tumor environment,resulting in the specific release of the active therapeutic agent.Certain peptide linkers will include a cleavage site that is recognizedby one or more enzymes involved in remodeling.

Peptide linkers that include a cleavage site for urokinase,pro-urokinase, plasmin, plasminogen, TGFβ, staphylokinase, Thrombin,Factor IXa, Factor Xa or a metalloproteinase, such as an interstitialcollagenase, a gelatinase or a stromelysin, are particularly preferred.U.S. Pat. Nos. 6,004,555, 5,877,289, and 6,093,399 are specificallyincorporated herein by reference for the purpose of further describingand enabling how to make and use immunoconjugates comprisingbiologically-releasable bonds and selectively-cleavable linkers andpeptides. U.S. Pat. No. 5,877,289 is particularly incorporated herein byreference for the purpose of further describing and enabling how to makeand use immunoconjugates that comprise a selectively-cleavable peptidelinker that is cleaved by urokinase, plasmin, Thrombin, Factor IXa,Factor Xa or a metalloproteinase, such as an interstitial collagenase, agelatinase or a stromelysin, within a tumor environment.

Currently preferred selectively-cleavable peptide linkers are those thatinclude a cleavage site for plasmin or a metalloproteinase (also knownas “matrix metalloproteases” or “MMPs”), such as an interstitialcollagenase, a gelatinase or a stromelysin. Additional peptide linkersthat may be advantageously used in connection with the present inventioninclude, for example, plasmin cleavable sequences, such as thosecleavable by pro-urokinase, TGFβ, plasminogen and staphylokinase; FactorXa cleavable sequences; MMP cleavable sequences, such as those cleavableby gelatinase A; collagenase cleavable sequences, such as thosecleavable by calf skin collagen (α1(I) chain), calf skin collagen (α2(I)chain), bovine cartilage collagen (α1(II)chain), human liver collagen(α1(III) chain), human α₂M, human PZP, rat α₁M, rat α₂M, rat α₁I₃(2J),rat α₁I₃(27J), and the human fibroblast collagenase autolytic cleavagesites. In addition to the knowledge available to those of ordinary skillin the art, the text and sequences from Table B2 in co-owned U.S. Pat.Nos. 6,342,219, 6,524,583, 6,342,221 and 6,416,758, are specificallyincorporated herein by reference for purposes of even further describingand enabling the use of such cleavable sequences.

H3. Bispecific Antibodies

Bispecific antibodies in general may be employed, so long as one armbinds to an aminophospholipid or anionic phospholipid and the bispecificantibody is attached, at a site distinct from the antigen binding site,to a therapeutic agent.

In general, the preparation of bispecific antibodies is also well knownin the art. One method involves the separate preparation of antibodieshaving specificity for the aminophospholipid or anionic phospholipid, onthe one hand, and a therapeutic agent on the other. Peptic F(ab′γ)₂fragments are prepared from the two chosen antibodies, followed byreduction of each to provide separate Fab′γ_(SH) fragments. The SHgroups on one of the two partners to be coupled are then alkylated witha cross-linking reagent such as O-phenylenedimaleimide to provide freemaleimide groups on one partner. This partner may then be conjugated tothe other by means of a thioether linkage, to give the desired F(ab′γ)₂heteroconjugate. Other techniques are known wherein cross-linking withSPDP or protein A is carried out, or a trispecific construct isprepared.

Another method for producing bispecific antibodies is by the fusion oftwo hybridomas to form a quadroma. As used herein, the term “quadroma”is used to describe the productive fusion of two B cell hybridomas.Using now standard techniques, two antibody producing hybridomas arefused to give daughter cells, and those cells that have maintained theexpression of both sets of clonotype immunoglobulin genes are thenselected.

A preferred method of generating a quadroma involves the selection of anenzyme deficient mutant of at least one of the parental hybridomas. Thisfirst mutant hybridoma cell line is then fused to cells of a secondhybridoma that had been lethally exposed, e.g., to iodoacetamide,precluding its continued survival. Cell fusion allows for the rescue ofthe first hybridoma by acquiring the gene for its enzyme deficiency fromthe lethally treated hybridoma, and the rescue of the second hybridomathrough fusion to the first hybridoma. Preferred, but not required, isthe fusion of immunoglobulins of the same isotype, but of a differentsubclass. A mixed subclass antibody permits the use if an alternativeassay for the isolation of a preferred quadroma.

In more detail, one method of quadroma development and screeninginvolves obtaining a hybridoma line that secretes the first chosen MAband making this deficient for the essential metabolic enzyme,hypoxanthine-guanine phosphoribosyltransferase (HGPRT). To obtaindeficient mutants of the hybridoma, cells are grown in the presence ofincreasing concentrations of 8-azaguanine (1×10⁻⁷M to 1×10⁻⁵M). Themutants are subcloned by limiting dilution and tested for theirhypoxanthine/aminopterin/thymidine (HAT) sensitivity. The culture mediummay consist of, for example, DMEM supplemented with 10% FCS, 2 mML-Glutamine and 1 mM penicillin-streptomycin.

A complementary hybridoma cell line that produces the second desired MAbis used to generate the quadromas by standard cell fusion techniques.Briefly, 4.5×10⁷ HAT-sensitive first cells are mixed with 2.8×10⁷HAT-resistant second cells that have been pre-treated with a lethal doseof the irreversible biochemical inhibitor iodoacetamide (5 mM inphosphate buffered saline) for 30 minutes on ice before fusion. Cellfusion is induced using polyethylene glycol (PEG) and the cells areplated out in 96 well microculture plates. Quadromas are selected usingHAT-containing medium. Bispecific antibody-containing cultures areidentified using, for example, a solid phase isotype-specific ELISA andisotype-specific immunofluorescence staining.

In one identification embodiment to identify the bispecific antibody,the wells of microtiter plates (Falcon, Becton Dickinson Labware) arecoated with a reagent that specifically interacts with one of the parenthybridoma antibodies and that lacks cross-reactivity with bothantibodies. The plates are washed, blocked, and the supernatants (SNs)to be tested are added to each well. Plates are incubated at roomtemperature for 2 hours, the supernatants discarded, the plates washed,and diluted alkaline phosphatase-anti-antibody conjugate added for 2hours at room temperature. The plates are washed and a phosphatasesubstrate, e.g., P-Nitrophenyl phosphate (Sigma, St. Louis) is added toeach well. Plates are incubated, 3N NaOH is added to each well to stopthe reaction, and the OD₄₁₀ values determined using an ELISA reader.

In another identification embodiment, microtiter plates pre-treated withpoly-L-lysine are used to bind one of the target cells to each well, thecells are then fixed, e.g. using 1% glutaraldehyde, and the bispecificantibodies are tested for their ability to bind to the intact cell. Inaddition, FACS, immunofluorescence staining, idiotype specificantibodies, antigen binding competition assays, and other methods commonin the art of antibody characterization may be used in conjunction withthe present invention to identify preferred quadromas.

Following the isolation of the quadroma, the bispecific antibodies arepurified away from other cell products. This may be accomplished by avariety of protein isolation procedures, known to those skilled in theart of immunoglobulin purification. Means for preparing andcharacterizing antibodies are well known in the art (See, e.g.,Antibodies: A Laboratory Manual, 1988).

For example, supernatants from selected quadromas are passed overprotein A or protein G sepharose columns to bind IgG (depending on theisotype). The bound antibodies are then eluted with, e.g. a pH 5.0citrate buffer. The elute fractions containing the BsAbs, are dialyzedagainst an isotonic buffer. Alternatively, the eluate is also passedover an anti-immunoglobulin-sepharose column. The BsAb is then elutedwith 3.5 M magnesium chloride. BsAbs purified in this way are thentested for binding activity by, e.g., an isotype-specific ELISA andimmunofluorescence staining assay of the target cells, as describedabove.

Purified BsAbs and parental antibodies may also be characterized andisolated by SDS-PAGE electrophoresis, followed by staining with silveror Coomassie. This is possible when one of the parental antibodies has ahigher molecular weight than the other, wherein the band of the BsAbsmigrates midway between that of the two parental antibodies. Reductionof the samples verifies the presence of heavy chains with two differentapparent molecular weights.

H4. Fusion Proteins and Recombinant Expression

Antibodies to aminophospholipids and anionic phospholipids, includingthe 9D2 and 3G4 (ATCC 4545) antibodies and other competing antibodieswith improved properties, and PE-binding peptides, can also be used tocreate fusion proteins using molecular biological techniques. Any fusionprotein may be designed and made using any of the antibodies, PE-bindingpeptides and second or therapeutic agents disclosed herein and thoseknown in the art. The fusion protein technology is readily adaptable toprepare fusion proteins with other modifications, such as optimizationsin CDR sequences, linkage via a selectively cleavable peptide sequence,and such like.

The use of recombinant DNA techniques to achieve such ends is nowstandard practice to those of skill in the art. These methods include,for example, in vitro recombinant DNA techniques, synthetic techniquesand in vivo recombination/genetic recombination. DNA and RNA synthesismay, additionally, be performed using an automated synthesizers (see,for example, the techniques described in Sambrook et al., 1989).

The preparation of such a fusion protein generally entails thepreparation of a first and second DNA coding region and the functionalligation or joining of such regions, in frame, to prepare a singlecoding region that encodes the desired fusion protein. In the presentcontext, the antibody sequence will be joined in frame with a DNAsequence encoding a therapeutic agent. It is not generally believed tobe particularly relevant which portion of the immunoconjugate isprepared as the N-terminal region or as the C-terminal region.

Once the desired coding region has been produced, an expression vectoris created. Expression vectors contain one or more promoters upstream ofthe inserted DNA regions that act to promote transcription of the DNAand to thus promote expression of the encoded recombinant protein. Thisis the meaning of “recombinant expression”.

To obtain a so-called “recombinant” version of the immunoconjugate, thevector is expressed in a recombinant cell. The engineering of DNAsegment(s) for expression in a prokaryotic or eukaryotic system may beperformed by techniques generally known to those of skill in recombinantexpression. It is believed that virtually any expression system may beemployed in expression.

The immunoconjugates of the invention may be successfully expressed ineukaryotic expression systems, e.g., CHO cells, however, it isenvisioned that bacterial expression systems, such as E. coli pQE-60will be particularly useful for the large-scale preparation andsubsequent purification of the constructs, cDNAs may also be expressedin bacterial systems, with the encoded proteins being expressed asfusions with β-galactosidase, ubiquitin, Schistosoma japonicumglutathione S-transferase, and the like. It is believed that bacterialexpression will have advantages over eukaryotic expression in terms ofease of use and quantity of materials obtained thereby.

In terms of microbial expression, U.S. Pat. Nos. 5,583,013; 5,221,619;4,785,420; 4,704,362; and 4,366,246 are incorporated herein by referencefor the purposes of even further supplementing the present disclosure inconnection with the expression of genes in recombinant host cells.

Recombinantly produced immunoconjugates may be purified and formulatedfor human administration. Alternatively, nucleic acids encoding theimmunoconjugates may be delivered via gene therapy. Although nakedrecombinant DNA or plasmids may be employed, the use of liposomes orvectors is preferred. The ability of certain viruses to enter cells viareceptor-mediated endocytosis and to integrate into the host cell genomeand express viral genes stably and efficiently have made them attractivecandidates for the transfer of foreign genes into mammalian cells.Preferred gene therapy vectors for use in the present invention willgenerally be viral vectors.

Retroviruses have promise as gene delivery vectors due to their abilityto integrate their genes into the host genome, transferring a largeamount of foreign genetic material, infecting a broad spectrum ofspecies and cell types and of being packaged in special cell-lines.Other viruses, such as adenovirus, herpes simplex viruses (HSV),cytomegalovirus (CMV), and adeno-associated virus (AAV), such as thosedescribed by U.S. Pat. No. 5,139,941 (incorporated herein by reference),may also be engineered to serve as vectors for gene transfer.

Although some viruses that can accept foreign genetic material arelimited in the number of nucleotides they can accommodate and in therange of cells they infect, these viruses have been demonstrated tosuccessfully effect gene expression. However, adenoviruses do notintegrate their genetic material into the host genome and therefore donot require host replication for gene expression, making them ideallysuited for rapid, efficient, heterologous gene expression. Techniquesfor preparing replication-defective infective viruses are well known inthe art.

In certain further embodiments, the gene therapy vector will be HSV. Afactor that makes HSV an attractive vector is the size and organizationof the genome. Because HSV is large, incorporation of multiple genes orexpression cassettes is less problematic than in other smaller viralsystems. In addition, the availability of different viral controlsequences with varying performance (e.g., temporal, strength) makes itpossible to control expression to a greater extent than in othersystems. It also is an advantage that the virus has relatively fewspliced messages, further easing genetic manipulations. HSV also isrelatively easy to manipulate and can be grown to high titers.

Of course, in using viral delivery systems, one will desire to purifythe virion sufficiently to render it essentially free of undesirablecontaminants, such as defective interfering viral particles or pyrogenssuch that it will not cause any untoward reactions in the cell, animalor individual receiving the vector construct. A preferred means ofpurifying the vector involves the use of buoyant density gradients, suchas cesium chloride gradient centrifugation.

I. Binding, Functional and Screening Assays

Although the present invention has significant utility in animal andhuman treatment regimens, it also has many other specific and credibleuses, including practical uses in many in vitro embodiments. Certain ofthese uses are related to the specific binding properties of theantibodies, peptides and immunoconjugates. In that each of theconstructs of the invention include at least one antibody or peptidecomponent that binds to an aminophospholipid and/or an anionicphospholipid, they may be used in a variety of binding embodiments,including useful binding assays.

The presence of an attached agent, where relevant, although providingadvantageous properties, does not negate the utility of the firstantibody or peptide regions in any binding assay. Suitably usefulbinding assays thus include those commonly employed in the art, such asin immunoblots, Western blots, dot blots, RIAs, ELISAs,immunohistochemistry, fluorescent activated cell sorting (FACS),immunoprecipitation, affinity chromatography, and the like, as furtherdescribed herein.

Certain standard binding assays are those in which an antigen isimmobilized onto a solid support matrix, e.g., nitrocellulose, nylon ora combination thereof, such as in immunoblots, Western blots, ELISAs andrelated assays. Other important assays are those using cells, whereinthe components of the present invention can be used to assay for cellswith aminophospholipids and/or anionic phospholipids at the cellsurface. Such assays can be applied in pre-clinical testing, e.g.,regarding the design of drugs, testing the mechanism of action and/orselecting therapeutic agents for combined use.

Further in vitro assays are useful in the diagnosis of diseasesconnected with aberrant cell activation and/or apoptosis, whereintesting for the presence of aminophospholipids and/or anionicphospholipids at the cell surface would be particularly useful. Theconstructs of the invention may thus be used in conjunction with bothfresh-frozen and formalin-fixed, paraffin-embedded tissue blocks inimmunohistochemistry; in fluorescent activated cell sorting, flowcytometry or flow microfluorometry.

They constructs of the invention have further practical uses inimmunoprecipitation, antigen purification embodiments, such as affinitychromatography, even including, in cases of bispecific antibodies, theone-step rapid purification of one or more antigens at the same time;and in many other binding assays that will be known to those of skill inthe art given the information presented herein.

Yet further practical uses of the present constructs are as controls infunctional assays, including many in vitro and ex vivo assays andsystems. As the binding and functional properties of the antibodies,peptides and conjugates of the invention are particularly specific, asdisclosed herein, such “control” uses are actually extremely valuable.The assays that benefit from such a practical application of the presentinvention include, for example, assays concerning detection ofaminophospholipids and/or anionic phospholipids at the cell surface.

These assays systems can also be developed into in vitro or ex vivo drugscreening assays, wherein the present provision of biological materialswith well defined properties is particularly important. For example, inusing the constructs of the present invention as positive controls inthe selection of small molecules that have similar, equivalent orimproved binding properties, e.g., in drug screening and development.

The binding assays and systems of the invention can also be developedinto in vitro or ex vivo drug screening assays, wherein the presentprovision of biological materials with well defined properties, as inthe antibodies disclosed herein, is particularly important. For example,in using the constructs of the present invention as positive controls inthe selection of small molecules that have similar, equivalent orimproved binding properties, e.g., in drug screening and development.

In this regard, the invention further provides methods of screening forcompounds that mimic the binding and activity of the antibodiesdisclosed herein, preferably the 9D2 or 3G4 antibodies, and mostpreferably the 3G4 (ATCC 4545) antibody. As the antibodies of theinvention bind to aminophospholipids and anionic phospholipids,preferably PS and PE, preferred screening methods are those that testcompounds for the ability to inhibit the binding of the antibodies toone or more aminophospholipids or anionic phospholipids, such as PS andPE. The methods are suitable for use in screening for low molecularweight compounds for use as drugs that mimic the anti-tumor,anti-vascular and/or anti-viral activities of the antibodies.

The “screening assays or methods” of the invention are conducted on thesame principles as the techniques employed in testing competing orcross-reactive antibodies, as taught herein and further exemplified inthe working examples. The starting materials, steps, qualitative andquantitative guidelines for use in the antibody competition assays maythus be readily adapted for use in the present screening assays,particularly in light of the following information.

In the screening methods, the agents to be tested may be termed“candidate substances”. Candidate substances for screening in suchassays include those isolated from natural sources, including bacteria,fungi, plant sources, including leaves and bark, soil and marinesamples. Other candidate substances that may be screened in this mannerare those derived from chemical compositions or man-made compounds,particularly those in large chemical libraries.

As with the methods for identifying competing antibodies, the screeningassays test the ability of a candidate substance to inhibit binding of a“control positive antibody”, such as the 3G4 antibody, to anaminophospholipid or anionic phospholipid, preferably PS. Antibodybinding is first measured in the absence of the candidate substance,which is preferably repeated once in each assay, but can also bereferred to from a known standard. The candidate substance(s) are thenadmixed with samples of the antibody and the ability of the antibody tobind to the target, preferably PS, is determined in the presence of thecandidate substance. A substance that reduces binding, and preferablysignificantly reduces binding, in comparison to the level in the absenceof the substance, is indicative of a candidate substance withcompetitive capability. Such substances are “positive candidatesubstances” and are continued for further development.

In preferred embodiments, the screening is conducted using PS-coatedmicrotiter plates. A high throughput screening procedure is consideredmost useful, many suitable examples of which are known and may now beused, in light of the motivation in the present disclosure, and inconjunction with the reagents provided by the invention. One example ofhigh throughput screening concerns testing compounds for the ability toinhibit the binding of luciferase-labeled antibodies, such asluciferase-labeled 3G4, to PS-coated microtiter plates.Luciferase-labeled 3G4 antibodies, and kits comprising such antibodies,are thus further components within the overall invention.

It is expected that suitable positive candidate substances will beidentified using the screening methods of the invention (notwithstandingthe fact that the screening assays are useful in themselves, evenwithout identifying effective candidate substances). If desired,chemical or biological modifications can be made to the positivecandidate substances first identified, and the modified versions or“analogs” re-screened to continue the process of selecting the mostuseful agents, e.g., to select more optimal inhibitory compounds fromchemical derivatives. Inhibitory activity can also be confirmed byre-screening after modifications based upon mechanistic considerations.For example, as cross-linking PS or PE on the target cells may berequired for optimal biological activity in vivo, positive candidatesubstances from the first screening assays may be linked to form dimers,trimers, oligomers or multimers and re-screened to confirm inhibitoryactivity, preferably followed by further tests to confirm cross-linkingin vitro.

J. Pharmaceutical Compositions

The therapeutic agents of the present invention will generally beformulated as pharmaceutical compositions. The pharmaceuticalcompositions will comprise a biologically or therapeutically effectiveamount of at least a first therapeutic agent of the invention, dissolvedor dispersed in a pharmaceutically acceptable carrier or aqueous medium.Combined therapeutics are also contemplated, and the same type ofunderlying pharmaceutical compositions may be employed for both singleand combined medicaments.

The phrases “pharmaceutically or pharmacologically acceptable” refer tomolecular entities and compositions that do not produce an adverse,allergic or other untoward reaction when administered to an animal, or ahuman, as appropriate. Veterinary uses are equally included within theinvention and “pharmaceutically acceptable” formulations includeformulations for both clinical and/or veterinary use.

As used herein, “pharmaceutically acceptable carrier” includes any andall solvents, dispersion media, coatings, antibacterial and antifungalagents, isotonic and absorption delaying agents and the like. The use ofsuch media and agents for pharmaceutical active substances is well knownin the art. Except insofar as any conventional media or agent isincompatible with the active ingredient, its use in the therapeuticcompositions is contemplated. For human administration, preparationsshould meet sterility, pyrogenicity, general safety and purity standardsas required by FDA Office of Biologics standards. Supplementary activeingredients can also be incorporated into the compositions.

“Unit dosage” formulations are those containing a dose or sub-dose ofthe administered ingredient adapted for a particular timed delivery. Forexample, exemplary “unit dosage” formulations are those containing adaily dose or unit or daily sub-dose or a weekly dose or unit or weeklysub-dose and the like.

J1. Injectable Formulations

The therapeutic agents of the invention will often be formulated forparenteral administration, particularly for tumor treatment, e.g.,formulated for injection via the intravenous, intramuscular,sub-cutaneous, transdermal, or other such routes, including peristalticadministration and direct instillation into a tumor or disease site(intracavity administration). The preparation of an aqueous compositionthat contains an antibody, immunoconjugate or peptide conjugate as anactive ingredient will be known to those of skill in the art in light ofthe present disclosure. Typically, such compositions can be prepared asinjectables, either as liquid solutions or suspensions; solid formssuitable for using to prepare solutions or suspensions upon the additionof a liquid prior to injection can also be prepared; and thepreparations can also be emulsified.

The pharmaceutical forms suitable for injectable use include sterileaqueous solutions or dispersions; formulations including sesame oil,peanut oil or aqueous propylene glycol; and sterile powders for theextemporaneous preparation of sterile injectable solutions ordispersions. In all cases, the form should be sterile and fluid to theextent that syringability exists. It should be stable under theconditions of manufacture and storage and should be preserved againstthe contaminating action of microorganisms, such as bacteria and fungi.

The therapeutic agents can be formulated into a sterile aqueouscomposition in a neutral or salt form. Solutions of therapeutic agentsas free base or pharmacologically acceptable salts can be prepared inwater suitably mixed with a surfactant, such as hydroxypropylcellulose.Pharmaceutically acceptable salts, include the acid addition salts(formed with the free amino groups of the protein), and those that areformed with inorganic acids such as, for example, hydrochloric orphosphoric acids, or such organic acids as acetic, trifluoroacetic,oxalic, tartaric, mandelic, and the like. Salts formed with the freecarboxyl groups can also be derived from inorganic bases such as, forexample, sodium, potassium, ammonium, calcium, or ferric hydroxides, andsuch organic bases as isopropylamine, trimethylamine, histidine,procaine and the like.

Suitable carriers include solvents and dispersion media containing, forexample, water, ethanol, polyol (for example, glycerol, propyleneglycol, and liquid polyethylene glycol, and the like), suitable mixturesthereof, and vegetable oils. In many cases, it will be preferable toinclude isotonic agents, for example, sugars or sodium chloride. Theproper fluidity can be maintained, for example, by the use of a coating,such as lecithin, by the maintenance of the required particle size inthe case of dispersion and/or by the use of surfactants.

Under ordinary conditions of storage and use, all such preparationsshould contain a preservative to prevent the growth of microorganisms.The prevention of the action of microorganisms can be brought about byvarious antibacterial and antifungal agents, for example, parabens,chlorobutanol, phenol, sorbic acid, thimerosal, and the like. Prolongedabsorption of the injectable compositions can be brought about by theuse in the compositions of agents delaying absorption, for example,aluminum monostearate and gelatin.

Prior to or upon formulation, the therapeutic agents should beextensively dialyzed to remove undesired small molecular weightmolecules, and/or lyophilized for more ready formulation into a desiredvehicle, where appropriate. Sterile injectable solutions are prepared byincorporating the active agents in the required amount in theappropriate solvent with various of the other ingredients enumeratedabove, as desired, followed by filtered sterilization. Generally,dispersions are prepared by incorporating the various sterilized activeingredients into a sterile vehicle that contains the basic dispersionmedium and the required other ingredients from those enumerated above.

In the case of sterile powders for the preparation of sterile injectablesolutions, the preferred methods of preparation are vacuum-drying andfreeze-drying techniques that yield a powder of the active ingredient,plus any additional desired ingredient from a previouslysterile-filtered solution thereof.

Suitable pharmaceutical compositions in accordance with the inventionwill generally include an amount of the therapeutic agent admixed withan acceptable pharmaceutical diluent or excipient, such as a sterileaqueous solution, to give a range of final concentrations, depending onthe intended use. The techniques of preparation are generally well knownin the art as exemplified by Remington's Pharmaceutical Sciences, 16thEd. Mack Publishing Company, 1980, incorporated herein by reference. Forhuman administration, preparations should meet sterility, pyrogenicity,general safety and purity standards as required by FDA Office ofBiological Standards. Upon formulation, the therapeutic agents will beadministered in a manner compatible with the dosage formulation and insuch amount as is therapeutically effective.

J2. Sustained Release Formulations

Formulations are easily administered in a variety of dosage forms, suchas the type of injectable solutions described above, but otherpharmaceutically acceptable forms are also contemplated, e.g., tablets,pills, capsules or other solids for oral administration, suppositories,pessaries, nasal solutions or sprays, aerosols, inhalants, topicalformulations, liposomal forms and the like. The type of form foradministration will be matched to the disease or disorder to be treated.

Pharmaceutical “slow release” capsules or “sustained release”compositions or preparations may also be used. Slow release formulationsare generally designed to give a constant drug level over an extendedperiod and may be used to deliver therapeutic agents in accordance withthe present invention. The slow release formulations are typicallyimplanted in the vicinity of the disease site, for example, at the siteof a tumor or viral infection.

Suitable examples of sustained-release preparations includesemipermeable matrices of solid hydrophobic polymers containingtherapeutic agents, which matrices are in the form of shaped articles,e.g., films or microcapsule. Examples of sustained-release matricesinclude polyesters; hydrogels, for example,poly(2-hydroxyethyl-methacrylate) or poly(vinylalcohol); polylactides,e.g., U.S. Pat. No. 3,773,919; copolymers of L-glutamic acid and γethyl-L-glutamate; non-degradable ethylene-vinyl acetate; degradablelactic acid-glycolic acid copolymers, such as the Lupron Depot™(injectable microspheres composed of lactic acid-glycolic acid copolymerand leuprolide acetate); and poly-D-(−)-3-hydroxybutyric acid.

While polymers such as ethylene-vinyl acetate and lactic acid-glycolicacid enable release of molecules for over 100 days, certain hydrogelsrelease proteins for shorter time periods. When encapsulated antibodiesremain in the body for a long time, they may denature or aggregate as aresult of exposure to moisture at 37° C., thus reducing biologicalactivity and/or changing immunogenicity. Rational strategies areavailable for stabilization depending on the mechanism involved. Forexample, if the aggregation mechanism involves intermolecular S—S bondformation through thio-disulfide interchange, stabilization is achievedby modifying sulfhydryl residues, lyophilizing from acidic solutions,controlling moisture content, using appropriate additives, developingspecific polymer matrix compositions, and the like.

J3. Liposomes and Nanocapsules

In certain embodiments, liposomes and/or nanoparticles may also beemployed with the therapeutic agents. The formation and use of liposomesis generally known to those of skill in the art, as summarized below.The present invention provides particular combinations of antibodies,liposomes and chemotherapeutic agents, which are described below. Inaddition, a liposomal formulation may be used as a routine component ofany of the therapeutic agents of the overall invention.

Liposomes are formed from phospholipids that are dispersed in an aqueousmedium and spontaneously form multilamellar concentric bilayer vesicles(also termed multilamellar vesicles (MLVs). MLVs generally havediameters of from 25 nm to 4 μm. Sonication of MLVs results in theformation of small unilamellar vesicles (SUVs) with diameters in therange of 200 to 500 Å, containing an aqueous solution in the core.

Phospholipids can form a variety of structures other than liposomes whendispersed in water, depending on the molar ratio of lipid to water. Atlow ratios the liposome is the preferred structure. The physicalcharacteristics of liposomes depend on pH, ionic strength and thepresence of divalent cations. Liposomes can show low permeability toionic and polar substances, but at elevated temperatures undergo a phasetransition which markedly alters their permeability. The phasetransition involves a change from a closely packed, ordered structure,known as the gel state, to a loosely packed, less-ordered structure,known as the fluid state. This occurs at a characteristicphase-transition temperature and results in an increase in permeabilityto ions, sugars and drugs.

Liposomes interact with cells via four different mechanisms: Endocytosisby phagocytic cells of the reticuloendothelial system such asmacrophages and neutrophils; adsorption to the cell surface, either bynonspecific weak hydrophobic or electrostatic forces, or by specificinteractions with cell-surface components; fusion with the plasma cellmembrane by insertion of the lipid bilayer of the liposome into theplasma membrane, with simultaneous release of liposomal contents intothe cytoplasm; and by transfer of liposomal lipids to cellular orsubcellular membranes, or vice versa, without any association of theliposome contents. Varying the liposome formulation can alter whichmechanism is operative, although more than one may operate at the sametime.

Nanocapsules can generally entrap compounds in a stable and reproducibleway. To avoid side effects due to intracellular polymeric overloading,such ultrafine particles (sized around 0.1 μm) should be designed usingpolymers able to be degraded in vivo. Biodegradablepolyalkyl-cyanoacrylate nanoparticles that meet these requirements arecontemplated for use in the present invention, and such particles may beare easily made.

J4. Ophthalmic Formulations

Many diseases of the eye, particularly those having an angiogeniccomponent, can be treated by the present invention. For example ocularneovascular disease, age-related macular degeneration, diabeticretinopathy, retinopathy of prematurity, corneal graft rejection,neovascular glaucoma, retrolental fibroplasias and other diseasesassociated with corneal neovascularization or retinal/choroidalneovascularization, as described hereinbelow.

The therapeutic agents of the present invention may thus beadvantageously employed in the preparation of pharmaceuticalcompositions suitable for use as ophthalmic solutions, including thosefor intravitreal and/or intracameral administration. For the treatmentof any of the foregoing or other disorders the therapeutic agents areadministered to the eye or eyes of the subject in need of treatment inthe form of an ophthalmic preparation prepared in accordance withconventional pharmaceutical practice, see for example “Remington'sPharmaceutical Sciences” 15th Edition, pages 1488 to 1501 (MackPublishing Co., Easton, Pa.).

The ophthalmic preparations will contain a therapeutic agent in aconcentration from about 0.01 to about 1% by weight, preferably fromabout 0.05 to about 0.5% in a pharmaceutically acceptable solution,suspension or ointment. Some variation in concentration will necessarilyoccur, depending on the particular compound employed, the condition ofthe subject to be treated and the like, and the person responsible fortreatment will determine the most suitable concentration for theindividual subject. The ophthalmic preparation will preferably be in theform of a sterile aqueous solution containing, if desired, additionalingredients, for example preservatives, buffers, tonicity agents,antioxidants and stabilizers, nonionic wetting or clarifying agents,viscosity-increasing agents and the like.

Suitable preservatives for use in such a solution include benzalkoniumchloride, benzethonium chloride, chlorobutanol, thimerosal and the like.Suitable buffers include boric acid, sodium and potassium bicarbonate,sodium and potassium borates, sodium and potassium carbonate, sodiumacetate, sodium biphosphate and the like, in amounts sufficient tomaintain the pH at between about pH 6 and pH 8, and preferably, betweenabout pH 7 and pH 7.5. Suitable tonicity agents are dextran 40, dextran70, dextrose, glycerin, potassium chloride, propylene glycol, sodiumchloride, and the like, such that the sodium chloride equivalent of theophthalmic solution is in the range 0.9 plus or minus 0.2%.

Suitable antioxidants and stabilizers include sodium bisulfite, sodiummetabisulfite, sodium thiosulfite, thiourea and the like. Suitablewetting and clarifying agents include polysorbate 80, polysorbate 20,poloxamer 282 and tyloxapol. Suitable viscosity-increasing agentsinclude dextran 40, dextran 70, gelatin, glycerin,hydroxyethylcellulose, hydroxmethylpropylcellulose, lanolin,methylcellulose, petrolatum, polyethylene glycol, polyvinyl alcohol,polyvinylpyrrolidone, carboxymethylcellulose and the like. Theophthalmic preparation will be administered topically to the eye of thesubject in need of treatment by conventional methods, for example in theform of drops or by bathing the eye in the ophthalmic solution.

J5. Topical Formulations

In the broadest sense, formulations for topical administration includethose for delivery via the mouth (buccal) and through the skin. “Topicaldelivery systems” also include transdermal patches containing theingredient to be administered. Delivery through the skin can further beachieved by iontophoresis or electrotransport, if desired.

Formulations suitable for topical administration in the mouth includelozenges comprising the ingredients in a flavored basis, usually sucroseand acacia or tragacanth; pastilles comprising the active ingredient inan inert basis such as gelatin and glycerin, or sucrose and acacia; andmouthwashes comprising the ingredient to be administered in a suitableliquid carrier.

Formulations suitable for topical administration to the skin includeointments, creams, gels and pastes comprising the ingredient to beadministered in a pharmaceutical acceptable carrier. The formulation oftherapeutic agents for topical use, such as in creams, ointments andgels, includes the preparation of oleaginous or water-soluble ointmentbases, will be well known to those in the art in light of the presentdisclosure. For example, these compositions may include vegetable oils,animal fats, and more preferably, semisolid hydrocarbons obtained frompetroleum. Particular components used may include white ointment, yellowointment, cetyl esters wax, oleic acid, olive oil, paraffin, petrolatum,white petrolatum, spermaceti, starch glycerite, white wax, yellow wax,lanolin, anhydrous lanolin and glyceryl monostearate. Variouswater-soluble ointment bases may also be used, including glycol ethersand derivatives, polyethylene glycols, polyoxyl 40 stearate andpolysorbates.

Formulations for rectal administration may be presented as a suppositorywith a suitable base comprising, for example, cocoa butter or asalicylate. Formulations suitable for vaginal administration may bepresented as pessaries, tampons, creams, gels, pastes, foams or sprayformulations containing in addition to the active ingredient suchcarriers as are known in the art to be appropriate.

J6. Nasal Formulations

Local delivery via the nasal and respiratory routes is contemplated fortreating various conditions, particularly for use in the anti-viraltreatment methods of the present invention. These delivery routes arealso suitable for delivering agents into the systemic circulation.Formulations of active ingredients in carriers suitable for nasaladministration are therefore also included within the invention, forexample, nasal solutions, sprays, aerosols and inhalants. Where thecarrier is a solid, the formulations include a coarse powder having aparticle size, for example, in the range of 20 to 500 microns, which isadministered, e.g., by rapid inhalation through the nasal passage from acontainer of the powder held close up to the nose.

Suitable formulations wherein the carrier is a liquid are useful innasal administration. Nasal solutions are usually aqueous solutionsdesigned to be administered to the nasal passages in drops or sprays andare prepared so that they are similar in many respects to nasalsecretions, so that normal ciliary action is maintained. Thus, theaqueous nasal solutions usually are isotonic and slightly buffered tomaintain a pH of 5.5 to 6.5. In addition, antimicrobial preservatives,similar to those used in ophthalmic preparations, and appropriate drugstabilizers, if required, may be included in the formulation. Variouscommercial nasal preparations are known and include, for example,antibiotics and antihistamines and are used for asthma prophylaxis.

Inhalations and inhalants are pharmaceutical preparations designed fordelivering a drug or compound into the respiratory tree of a patient. Avapor or mist is administered and reaches the affected area. This routecan also be employed to deliver agents into the systemic circulation.Inhalations may be administered by the nasal or oral respiratory routes.The administration of inhalation solutions is only effective if thedroplets are sufficiently fine and uniform in size so that the mistreaches the bronchioles.

Another group of products, also known as inhalations, and sometimescalled insufflations, comprises finely powdered or liquid drugs that arecarried into the respiratory passages by the use of special deliverysystems, such as pharmaceutical aerosols, that hold a solution orsuspension of the drug in a liquefied gas propellant. When releasedthrough a suitable valve and oral adapter, a metered does of theinhalation is propelled into the respiratory tract of the patient.Particle size is of major importance in the administration of this typeof preparation. It has been reported that the optimum particle size forpenetration into the pulmonary cavity is of the order of 0.5 to 7 μm.Fine mists are produced by pressurized aerosols and hence their use inconsidered advantageous.

K. Diagnostic and Therapeutic Kits

This invention also provides diagnostic and therapeutic kits comprisingat least a first therapeutic agent of the present invention, i.e., anantibody, immunoconjugate or peptide conjugate that binds to anaminophospholipid or anionic phospholipid, for use in treatment methods,combined treatment methods and/or in imaging and treatment embodiments.Such kits will generally contain, in at least a first suitable container(or container means), a pharmaceutically acceptable formulation of atleast one therapeutic agent, antibody, immunoconjugate or peptideconjugate that binds to an aminophospholipid or anionic phospholipid.The kits may include written or electronic instructions for use, e.g. inpre-clinical, clinical and/or veterinary embodiments.

The kits may also contain other compositions, pharmaceuticallyacceptable formulations and second biological and therapeutic agents,including those for combined therapy and/or for diagnostic and imaging.For example, such kits may contain any one or more of a range ofchemotherapeutic, radiotherapeutic or anti-angiogenic agents, anti-tumorcell, anti-tumor vasculature or anti-tumor stroma antibodies,immunotoxins or coaguligands, anti-viral agents and/or diagnosticcomponents or agents. Written or electronic instructions for use incombined therapy and/or for diagnosis and imaging may also be included.

The kits may have a single container that contains the first antibody,immunoconjugate or peptide conjugate that binds to an aminophospholipidor anionic phospholipid, with or without any additional components, orthey may have distinct containers for each desired agent. Where combinedtherapeutics are provided, a single solution may be pre-mixed, either ina molar equivalent combination, or with one component in excess of theother. Alternatively, the primary therapeutic agent of the invention andthe second biological or therapeutic agent, such as a second anti-canceror anti-viral agent, kit may be maintained separately within distinctcontainers of the kit prior to administration to a patient.

Diagnostic components will most often be maintained in at least a secondcontainer, distinct from the other or first container that comprises theone or more therapeutic agents. The diagnostic kits may include labeledantibodies or peptides that bind to the same aminophospholipid oranionic phospholipid as the primary therapeutic agent, or any otheragent suitable for diagnosing the disease to be treated. The kits mayinclude diagnostic agents for use in vitro, for use in vivo, or bothsuch agent. The kits may include written or electronic instructions foruse, e.g. in pre-clinical, clinical and/or veterinary diagnosticembodiments.

For immunodetection in vitro, the antibodies may be bound to a solidsupport, such as a well of a microtitre plate, although antibodysolutions or powders for reconstitution are preferred. Theimmunodetection kits preferably comprise at least a firstimmunodetection reagent. The immunodetection reagents of the kit maytake any one of a variety of forms, including those detectable labelsthat are associated with or linked to the given antibody, such as usedin vivo. Detectable labels that are associated with or attached to asecondary binding ligand are also contemplated. Exemplary secondaryligands are those secondary antibodies that have binding affinity forthe first antibody.

Further suitable immunodetection reagents for use in the present kitsinclude the two-component reagent that comprises a secondary antibodythat has binding affinity for the first antibody, along with a thirdantibody that has binding affinity for the second antibody, the thirdantibody being linked to a detectable label. A number of exemplarylabels are known in the art and all such labels may be employed inconnection with the present invention. These kits may containantibody-label conjugates either in fully conjugated form, in the formof intermediates, or as separate moieties to be conjugated by the userof the kit. The imaging kits will preferably comprise a targeting agentor antibody that is already attached to an in vivo detectable label.However, the label and attachment means could be separately supplied.

Either form of diagnostic kit may further comprise control agents, suchas suitably aliquoted biological compositions, whether labeled orunlabeled, as may be used to prepare a standard curve for a detectionassay. The components of the kits may be packaged either in aqueousmedia or in lyophilized form.

When the components of the kit are provided in one or more liquidsolutions, the liquid solution is preferably an aqueous solution, with asterile aqueous solution being particularly preferred. However, thecomponents of the kit may be provided as dried powder(s). When reagentsor components are provided as a dry powder, the powder can bereconstituted by the addition of a suitable solvent. The solvent mayalso be provided in another container within the kit.

The containers of the therapeutic and diagnostic kits will generallyinclude at least one vial, test tube, flask, bottle, syringe or othercontainer or container means, into which the therapeutic and any otherdesired agent are placed and, preferably, suitably aliquoted. As atleast two separate components are preferred, the kits will preferablyinclude at least two such containers. The kits may also comprise a thirdor fourth container for containing a sterile, pharmaceuticallyacceptable buffer or other diluent.

The kits may also contain a means by which to administer the therapeuticagents to an animal or patient, e.g., one or more needles or syringes,or even an eye dropper, pipette, or other such like apparatus, fromwhich the formulations may be injected into the animal or applied to adiseased area of the body. The kits of the present invention will alsotypically include a means for containing the vials, or such like, andother component, in close confinement for commercial sale, such as,e.g., injection or blow-molded plastic containers into which the desiredvials and other apparatus are placed and retained.

L. Immunodetection and Imaging

The present invention further provides in vitro and in vivo diagnosticand imaging methods. Such methods are applicable for use in generatingdiagnostic, prognostic and/or imaging information, e.g., related toangiogenic diseases and viral infections, and preferably related totumor treatment and imaging methods. The methods of the inventioninclude in vitro diagnostic tests, e.g., wherein the samples can beobtained non-invasively and preferably tested in high throughput assaysand/or where the clinical diagnosis in ambiguous and confirmation isdesired. In the field of in vivo diagnostics and imaging, the antibodiesand peptides of the invention are linked to one or more detectableagents and used to form an image of an angiogenic site or tumor,optionally as a first step prior to treatment.

L1. Immunodetection Methods and Kits

The invention thus concerns immunodetection methods for binding,purifying, quantifying or otherwise generally detectingaminophospholipids and anionic phospholipids, e.g., for use indiagnosing activated and apoptotic cells and associated diseases. Theantibodies of the present invention, such as 9D2 and 3G4 (ATCC 4545),may be employed to detect aminophospholipids and anionic phospholipidsin vivo (see below), in isolated issue samples, biopsies or swabs and/orin homogenized tissue samples. Such immunodetection methods have evidentdiagnostic utility, but also have applications to non-clinical samples,such as in the titering of antigen samples, and the like.

The steps of various useful immunodetection methods have been describedin the scientific literature, such as, e.g., Nakamura et al., 1987,specifically incorporated herein by reference. In general, theimmunobinding methods include obtaining a sample suspected of containingaminophospholipids and/or anionic phospholipids, preferably cellssuspected of having aminophospholipids and/or anionic phospholipids atthe cell surface, and contacting the sample with an antibody of theinvention, such as 9D2 or 3G4 (ATCC 4545), under conditions effective toallow the formation of immune complexes. Any immune complexes formedduring the binding process are then detected and preferably quantified.

The sample analyzed may be a cell sample, such as cells exposed tocertain test conditions in the laboratory. The sample may also be abiological sample from an animal or patient, e.g., one suspected ofhaving a disease associated with activation or apoptosis of one or morecell types. Such a sample may be a tissue section or specimen, a biopsy,a swab or smear test sample, a homogenized tissue extract or separatedor purified forms of such.

Contacting the chosen biological sample with the antibody underconditions effective and for a period of time sufficient to allow theformation of immune complexes (primary immune complexes) is generally amatter of simply adding the antibody to the sample and incubating themixture for a period of time long enough for the antibodies to formimmune complexes with, i.e., to bind to, any aminophospholipids and/oranionic phospholipids present. After this time, the sample-antibodycomposition, such as a tissue section or ELISA plate, will generally bewashed to remove any non-specifically bound antibody species, allowingonly those antibodies specifically bound within the primary immunecomplexes to be detected.

The detection of immunocomplex formation is well known in the art andmay be achieved through the application of numerous approaches. Thesemethods are generally based upon the detection of a label or marker,such as any radioactive, fluorescent, biological or enzymatic tags orlabels known in the art. U.S. Patents concerning the use of such labelsinclude U.S. Pat. Nos. 3,817,837; 3,850,752; 3,939,350; 3,996,345;4,277,437; 4,275,149 and 4,366,241, each incorporated herein byreference. The use of enzymes that generate a colored product uponcontact with a chromogenic substrate are generally preferred. Secondarybinding ligands, such as a second antibody or a biotin/avidin ligandbinding arrangement, may also be used, as is known in the art.

The antibodies of the invention, such as 9D2 and 3G4 (ATCC 4545),employed in the detection may themselves be linked to a detectablelabel, wherein one would then simply detect this label, thereby allowingthe amount of the primary immune complexes in the composition to bedetermined.

Preferably, the primary immune complexes are detected by means of asecond binding ligand that has binding affinity for the antibodies ofthe invention. In such cases, the second binding ligand may be linked toa detectable label. The second binding ligand is itself often anantibody, and may thus be termed a “secondary” antibody. The primaryimmune complexes are contacted with the labeled, secondary bindingligand, or antibody, under conditions effective and for a period of timesufficient to allow the formation of secondary immune complexes. Thesecondary immune complexes are then generally washed to remove anynon-specifically bound labeled secondary antibodies or ligands, and theremaining label in the secondary immune complexes is then detected.

Further methods include the detection of primary immune complexes by atwo step approach. A second binding ligand, such as an antibody, thathas binding affinity for the first antibody is used to form secondaryimmune complexes, as described above. After washing, the secondaryimmune complexes are contacted with a third binding ligand or antibodythat has binding affinity for the second antibody, again underconditions effective and for a period of time sufficient to allow theformation of immune complexes (tertiary immune complexes). The thirdligand or antibody is linked to a detectable label, allowing detectionof the tertiary immune complexes thus formed. This system may providefor signal amplification if desired.

Clinical diagnosis or monitoring may be applied to patients with avariety of diseases, particularly those associated with increasedaminophospholipid and/or anionic phospholipid exposure at the cellsurface. The detection of an aminophospholipid and/or anionicphospholipid, or an increase in the levels of an aminophospholipidand/or anionic phospholipid, in comparison to the levels in acorresponding biological sample from a normal subject, is indicative ofa patient with such a disease.

However, as is known to those of skill in the art, such a clinicaldiagnosis would not likely be made on the basis of this method inisolation. Those of skill in the art are very familiar withdifferentiating between significant expression of a biomarker, whichrepresents a positive identification, and low level or backgroundexpression of a biomarker. Indeed, background expression levels areoften used to form a “cut-off” above which increased staining will bescored as significant or positive.

L2. In Vivo Imaging

The present invention provides a variety of in vivo diagnostic andimaging embodiments. Certain aspects of the invention concern new andsurprisingly effective compositions for in vivo diagnosis and imaging.For example, any one or more of the panel of new anti-PS antibodies ofthe invention, preferably the 9D2 or 3G4 (ATCC 4545) antibodies orcompeting antibodies with like properties, are linked to an in vivodetectable agent to form an immunodiagnostic conjugate of the invention.Although the antibodies represent an important development in the field,the resultant immunodiagnostics may now be used in any previouslydescribed diagnostic or imaging embodiment connected with the detectionof an aminophospholipid and/or anionic phospholipid.

In this regard, immunodiagnostics comprising an antibody of theinvention, including the 9D2 or 3G4 (ATCC 4545) antibodies or competingantibodies with like properties, may be used in imaging vascularthromboses, particularly in or near the heart, such as in deep veinthrombosis, pulmonary embolism, myocardial infarction, atrialfibrillation, problems with prosthetic cardiovascular materials, stroke,and the like. Such compositions of the invention may also be used inimaging activated platelets, e.g., in conditions such as abscesses,restenosis, inflammation of joints and in hemostatic disorders, such asarterial, coronary, venous and cerebral thrombosis and the like. Theimmunodiagnostic compositions of the invention, preferably thosecomprising the 9D2 or 3G4 (ATCC 4545) antibodies or competing antibodieswith like properties, may also be used in detecting apoptotic cells, asmay be used in the diagnosis and imaging of a variety of diseases inwhich increased or inappropriate apoptosis occurs.

The invention further provides a range of new methods for in vivodiagnosis and imaging, which are not limited to the use of the panel ofantibodies provided herein. For example, in light of the unexpectedfinding that anionic phospholipids such as PI, PA and PG are accessibleand stably targetable markers of tumor vasculature, the inventionprovides methods for diagnosing and imaging tumors comprisingadministration of an immunodiagnostic that binds to PI, PA or PG, whichwill specifically localize to the vasculature of solid tumors. Inaddition, virally infected cells can now be detected, and viralinfections diagnosed, using an immunodiagnostic conjugate that binds toan aminophospholipid and/or an anionic phospholipid, such as PS, PE, PI,PA and PG, and preferably PS and PE.

The in vivo imaging compositions and methods of the invention can beused in imaging per se, or in pre-imaging a site in the body to form areliable image prior to treatment. Preferably, the imaging is tumorimaging. These compositions and methods can also be applied to imagingand diagnosis of other diseases or conditions associated withaminophospholipids and anionic phospholipids, such those involving cellactivation and/or apoptosis, including angiogenic diseases,atherosclerosis, viral infections, and other such conditions in which aninternal image is desired for diagnostic or prognostic purposes or todesign treatment.

In these embodiments, antibodies and peptides, preferably the antibodiesof the invention, such as the 9D2, 3G4 (ATCC 4545) and like antibodies,are operatively attached, linked or conjugated to a detectable label.“Detectable labels” are compounds or elements that can be detected dueto their specific functional properties, or chemical characteristics,the use of which allows the component to which they are attached to bedetected, and further quantified if desired. In antibody and peptideconjugates for in vivo diagnostic protocols or “imaging methods”, thelabels can be detected using non-invasive methods.

Many appropriate imaging agents are known in the art, as are methods fortheir attachment to antibodies and binding ligands (see, e.g., U.S. Pat.Nos. 5,021,236 and 4,472,509, both incorporated herein by reference).Certain attachment methods involve the use of a metal chelate complexemploying, for example, an organic chelating agent such a DTPA attachedto the antibody (U.S. Pat. No. 4,472,509). Monoclonal antibodies mayalso be reacted with an enzyme in the presence of a coupling agent suchas glutaraldehyde or periodate. Conjugates with fluorescein markers areprepared in the presence of these coupling agents or by reaction with anisothiocyanate.

An example of detectable labels are the paramagnetic ions. In this case,suitable ions include chromium (III), manganese (II), iron (III), iron(II), cobalt (II), nickel (II), copper (II), neodymium (III), samarium(III), ytterbium (III), gadolinium (III), vanadium (II), terbium (III),dysprosium (III), holmium (III) and erbium (II), with gadolinium beingparticularly preferred.

Ions useful in other contexts, such as X-ray imaging, include but arenot limited to lanthanum (III), gold (III), lead (II), and especiallybismuth (III). Fluorescent labels include rhodamine, fluorescein andrenographin. Rhodamine and fluorescein are often linked via anisothiocyanate intermediate.

In the case of radioactive isotopes for diagnostic applications,suitable examples include ¹⁴carbon, ⁵¹chromium, ³⁶chlorine, ⁵⁷cobalt,⁵⁸cobalt, copper⁶⁷, ¹⁵²Eu, gallium⁶⁷, ³hydrogen, iodine ²³, iodine¹²⁵,iodine¹³¹, indium¹¹¹, ⁵⁹iron, ³²phosphorus, rhenium¹⁸⁶, rhenium^(188,)⁷⁵selenium, ³⁵sulphur, technetium^(99m) and yttrium⁹⁰. ¹²⁵I is oftenbeing preferred for use in certain embodiments, and technicium^(99m) andindium¹¹¹ are also often preferred due to their low energy andsuitability for long range detection.

Radioactively labeled antibodies and peptides for use in the presentinvention may be produced according to well-known methods in the art.For instance, intermediary functional groups that are often used to bindradioisotopic metallic ions to antibodies arediethylenetriaminepentaacetic acid (DTPA) and ethylene diaminetetraceticacid (EDTA).

Monoclonal antibodies can also be iodinated by contact with sodium orpotassium iodide and a chemical oxidizing agent such as sodiumhypochlorite, or an enzymatic oxidizing agent, such as lactoperoxidase.Anti-tumor antibodies according to the invention may be labeled withtechnetium-99 by a ligand exchange process, for example, by reducingpertechnate with stannous solution, chelating the reduced technetiumonto a Sephadex column and applying the antibody to this column. Directlabeling techniques are also suitable, e.g., by incubating pertechnate,a reducing agent such as SNCl₂, a buffer solution such assodium-potassium phthalate solution, and the antibody.

Any of the foregoing type of detectably labeled antibodies and bindingligands may be used in the imaging aspects of the invention, either forimaging alone or to form an image of a disease site or tumor prior totreatment. Either way, the methods generally comprise administering toan animal or patient a diagnostically effective amount of an antibody orbinding ligand that is conjugated to a marker that is detectable bynon-invasive methods. The antibody- or binding ligand-marker conjugateis allowed sufficient time to localize and bind to cells expressingaminophospholipids and/or anionic phospholipids in the disease site,such as the tumor or tumor vasculature. The patient is then exposed to adetection device to identify the detectable marker, thus forming animage of the disease site or tumor.

The nuclear magnetic spin-resonance isotopes, such as gadolinium, aredetected using a nuclear magnetic imaging device; and radioactivesubstances, such as technicium^(99m) or indium¹¹¹, are detected using agamma scintillation camera or detector. U.S. Pat. No. 5,627,036 is alsospecifically incorporated herein by reference for purposes of providingeven further guidance regarding the safe and effective introduction ofdetectably labeled constructs into the blood of an individual, and meansfor determining the distribution of the detectably labeled agentextracorporally, e.g., using a gamma scintillation camera or by magneticresonance measurement.

Dosages for imaging embodiments are generally less than for therapy, butare also dependent upon the age and weight of a patient. A one time doseof between about 0.1, 0.5 or about 1 mg and about 9 or 10 mgs, and morepreferably, of between about 1 mg and about 5-10 mgs of antibody- orbinding ligand-conjugate per patient is contemplated to be useful.

L3. Surrogate Marker for Cancer Therapy

In regard to the in vivo diagnostic and imaging, the present inventionfurther provides compositions and methods for use as a surrogate markerfor cancer therapy. Such embodiments concern the use of an antibody thatbinds to an aminophospholipid and/or an anionic phospholipid, preferablyPS, and most preferably to the use of the 9D2 or 3G4 (ATCC 4545)antibodies or competing antibodies, linked to an in vivo detectableagent.

Many anti-cancer therapies in current use induce apoptosis and necrosis.Aminophospholipids and anionic phospholipids, particularly PS, aremarkers of pre-apoptotic and apoptotic cells. Therefore, imaging with asuitable antibody, preferably 9D2, 3G4 (ATCC 4545) or competingantibodies, can be used to identify pre-apoptotic and apoptotic cellsand thus provide information regarding the progress of the therapy. Thisis what is meant by a “surrogate marker for cancer therapy”, as usedherein.

The use of the antibodies of the invention, preferably those comprisingthe 9D2 or 3G4 (ATCC 4545) antibodies or competing antibodies with likeproperties, provides particular advantages as a surrogate marker forcancer therapy. For example, the ability to identify pre-apoptotic cellsis a particular advantage. The specificity of the antibodies will alsoprovide more meaningful imaging data for the physician. Also, the safetyprofile of these antibodies is impressive and provides advantages overannexin, for example, as annexin suffers from drawbacks associated withcoagulation.

Accordingly, any of the in vivo diagnostic and imaging methods describedabove may be adapted for prognostic use as a surrogate marker for cancertherapy simply by use in a patient undergoing cancer therapy.

M. Tumor Treatment

Important aspects of the present invention concern the treatment ofmalignancies, tumors and vascularized tumors. This includes tumors inwhich angiogenesis is more or less important and tumors havingprothrombotic blood vessels. The treatment of benign tumors is includedin the invention, such as acoustic neuroma, neurofibroma, trachoma,pyogenic granulomas and BPH. The treatment of blood-born tumors, such asleukemias, and various acute or chronic neoplastic diseases of the bonemarrow is also encompassed.

The present invention is broadly applicable to the treatment of anymalignant tumor, whether having a vascular component or not. Tumors fortreatment include solid tumors, particularly carcinomas, which require avascular component for the provision of oxygen and nutrients. Exemplarysolid tumors that may be treated using the invention include, but arenot limited to, carcinomas of the lung, breast, ovary, stomach,pancreas, larynx, esophagus, testes, liver, parotid, biliary tract,colon, rectum, cervix, uterus, endometrium, kidney, bladder, prostate,thyroid, squamous cell carcinomas, adenocarcinomas, small cellcarcinomas, melanomas, gliomas, glioblastomas, neuroblastomas, and thelike.

The present invention is contemplated for use in the treatment of anypatient that presents with a solid tumor. In general, the invention canbe used to treat tumors of all sizes, including those about 0.3-0.5 cmand upwards, tumors of greater than 0.5 cm in size and patientspresenting with tumors of between about 1.0 and about 2.0 cm in size,although tumors up to and including the largest tumors found in humansmay also be treated.

Although the present invention is not generally intended as apreventative or prophylactic treatment, use of the invention iscertainly not confined to the treatment of patients having tumors ofonly moderate or large sizes. There are many reasons underlying theseaspects of the invention. For example, a patient presenting with aprimary tumor of moderate size or above may also have various othermetastatic tumors that are considered to be small-sized or even in theearlier stages of metastatic tumor seeding. Given that theanti-aminophospholipid or anti-anionic phospholipid antibodies orPE-binding peptide derivatives, or combinations, of the invention aregenerally administered into the systemic circulation of a patient, theywill naturally have effects on the secondary, smaller and metastatictumors, although this may not be the primary intent of the treatment.Furthermore, even in situations where the tumor mass as a whole is asingle small tumor, certain beneficial anti-tumor effects will resultfrom the use of the present treatments.

The guidance provided herein regarding the suitable patients for use inconnection with the present invention is intended as teaching thatcertain patient's profiles may assist with the selection of patients fortreatment by the present invention. The pre-selection of certainpatients, or categories of patients, does not in any way negate thebasic usefulness of the present invention in connection with thetreatment of all patients having cancer. A further consideration is thefact that the assault on the tumor provided by the antibody therapy ofthe invention may predispose the tumor to further therapeutic treatment,such that the subsequent treatment results in an overall synergisticeffect or even leads to total remission or cure.

It is not believed that any particular type of tumor should be excludedfrom treatment using the present invention. However, the type of tumorcells may be relevant to the use of the invention in combination withtertiary therapeutic agents, particularly chemotherapeutics andanti-tumor cell immunotoxins. As the present invention includes withinits modes of action the targeting and destruction of tumor vasculature,and as the vasculature is substantially or entirely the same in allsolid tumors, it will be understood that the present methodology iswidely or entirely applicable to the treatment of all solid tumors,irrespective of the particular phenotype or genotype of the tumor cellsthemselves. The data presented herein is compelling as it showsimpressive results in a wide range of different tumor models.

Therapeutically effective doses are readily determinable using data froman animal model, as shown in the studies detailed herein, and fromclinical data using a range of therapeutic agents. Experimental animalsbearing solid tumors are frequently used to optimize appropriatetherapeutic doses prior to translating to a clinical environment. Suchmodels are known to be very reliable in predicting effective anti-cancerstrategies. For example, mice bearing solid tumors, such as used in theExamples, are widely used in pre-clinical testing. The inventors haveused such art-accepted mouse models to determine working ranges oftherapeutic agents that give beneficial anti-tumor effects with minimaltoxicity.

In terms of tumor therapy, bearing in mind the attendant safety benefitsassociated with the overall invention, one may refer to the scientificand patent literature on the success of using other anti-vasculartherapies. By way of example, U.S. Pat. Nos. 5,855,866; 5,877,289;5,965,132; 6,051,230; 6,004,555; 5,776,427; 6,004,554; 6,036,955; and6,093,399 are incorporated herein by reference for the purpose offurther describing the use of such agents as may be applied to those ofthe present invention. U.S. Pat. Nos. 6,312,694 and 6,406,693 arefurther specifically incorporated herein by reference for guidance ondosing and treatment using unconjugated antibodies to PS and PE andrelated immunoconjugates.

As is known in the art, there are realistic objectives that may be usedas a guideline in connection with pre-clinical testing before proceedingto clinical treatment. However, due to the safety already demonstratedin accepted models, pre-clinical testing of the present invention willbe more a matter of optimization, rather than to confirm effectiveness.Thus, pre-clinical testing may be employed to select the mostadvantageous agents, doses or combinations.

Any antibody dose, combined method or medicament that results in anyconsistently detectable anti-tumor effect, including detectable tumorvasculature regression, thrombosis and/or destruction and tumornecrosis, will still define a useful invention. Regressive, thrombotic,destructive and necrotic effects should preferably be observed inbetween about 10% and about 40-50% of the tumor blood vessels and tumortissues, upwards to between about 50% and about 99% of such effectsbeing observed. The present invention may also be effective againstvessels downstream of the tumor, i.e., target at least a sub-set of thedraining vessels, particularly as cytokines released from the tumor willbe acting on these vessels, changing their antigenic profile.

It will also be understood that even in such circumstances where theanti-tumor effects of the therapy are towards the low end of this range,it may be that this therapy is still equally or even more effective thanall other known therapies in the context of the particular tumor. It isunfortunately evident to a clinician that certain tumors cannot beeffectively treated in the intermediate or long term, but that does notnegate the usefulness of the present therapy, particularly where it isat least about as effective as the other strategies generally proposed.

In designing appropriate doses of anti-aminophospholipid or anti-anionicphospholipid antibodies, PE-binding peptide derivatives or combinedtherapeutics for the treatment of vascularized tumors, one may readilyextrapolate from the animal studies described herein in order to arriveat appropriate doses for clinical administration. To achieve thisconversion, one would account for the mass of the agents administeredper unit mass of the experimental animal and, preferably, account forthe differences in the body surface area between the experimental animaland the human patient. All such calculations are well known and routineto those of ordinary skill in the art.

For example, in taking the successful doses of therapeutics used in themouse studies, and applying standard calculations based upon mass andsurface area, effective doses of agents for use in human patients wouldbe between about 1 mg and about 500 mgs antibody per patient, andpreferably, between about 10 mgs and about 100 mgs antibody per patient.

Accordingly, using this information, the inventors contemplate thatuseful low doses for human administration will be about 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 15, 20, 25 or about 30 mgs or so per patient; and usefulhigh doses for human administration will be about 250, 275, 300, 325,350, 375, 400, 425, 450, 475 or about 500 mgs or so per patient. Usefulintermediate doses for human administration are contemplated to be about35, 40, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200 or about 225 mgs orso per patient. In general, dosage ranges of between about 5-100 mgs,about 10-80 mgs, about 20-70 mgs, about 25-60 mgs, or about 30-50 mgsper patient will be preferred. However, any particular range using anyof the foregoing recited exemplary doses or any value intermediatebetween the particular stated ranges is contemplated.

Notwithstanding the stated ranges, it will be understood that, given theparameters and detailed guidance presented herein, further variations inthe active or optimal ranges will be encompassed within the presentinvention. It will thus be understood that lower doses may be moreappropriate in combination with certain agents, and that high doses canstill be tolerated, particularly given the enhanced safety of thepresent constructs. The use of human or humanized antibodies and humaneffectors renders the present invention even safer for clinical use,further reducing the chances of significant toxicity or side effects inhealthy tissues.

The intention of the therapeutic regimens of the present invention isgenerally to produce significant anti-tumor effects whilst still keepingthe dose below the levels associated with unacceptable toxicity. Inaddition to varying the dose itself, the administration regimen can alsobe adapted to optimize the treatment strategy. A currently preferredtreatment strategy is to administer between about 1-500 mgs, andpreferably, between about 10-100 mgs of the antibody, or therapeuticcocktail containing such, about 3 times within about a 7 day period. Forexample, doses would be given on about day 1, day 3 or 4 and day 6 or 7.

In administering the particular doses themselves, one would preferablyprovide a pharmaceutically acceptable composition (according to FDAstandards of sterility, pyrogenicity, purity and general safety) to thepatient systemically. Intravenous injection is generally preferred, andthe most preferred method is to employ a continuous infusion over a timeperiod of about 1 or 2 hours or so. Although it is not required todetermine such parameters prior to treatment using the presentinvention, it should be noted that the studies detailed herein result inat least some thrombosis being observed specifically in the bloodvessels of a solid tumor within about 12-24 hours of injection, and thatthe tumor cells themselves begin to die within about 24 to 72 hours.Widespread tumor necrosis is generally observed in the next about 48-96hours, up to and including greater than 60% necrosis being observed.

Naturally, before wide-spread use, clinical trials will be conducted.The various elements of conducting a clinical trial, including patienttreatment and monitoring, will be known to those of skill in the art inlight of the present disclosure. The following information is beingpresented as a general guideline for use in establishing such trials.

Patients chosen for the first treatment studies will have failed torespond to at least one course of conventional therapy, and will haveobjectively measurable disease as determined by physical examination,laboratory techniques, and/or radiographic procedures. Any chemotherapyshould be stopped at least 2 weeks before entry into the study. Wheremurine monoclonal antibodies or antibody portions are employed, thepatients should have no history of allergy to mouse immunoglobulin.

Certain advantages will be found in the use of an indwelling centralvenous catheter with a triple lumen port. The therapeutics should befiltered, for example, using a 0.22μ filter, and diluted appropriately,such as with saline, to a final volume of 100 ml. Before use, the testsample should also be filtered in a similar manner, and itsconcentration assessed before and after filtration by determining theA₂₈₀. The expected recovery should be within the range of 87% to 99%,and adjustments for protein loss can then be accounted for.

The constructs may be administered over a period of approximately 4-24hours, with each patient receiving 2-4 infusions at 2-7 day intervals.Administration can also be performed by a steady rate of infusion over a7 day period. The infusion given at any dose level should be dependentupon any toxicity observed. Hence, if Grade II toxicity was reachedafter any single infusion, or at a particular period of time for asteady rate infusion, further doses should be withheld or the steadyrate infusion stopped unless toxicity improved. Increasing doses shouldbe administered to groups of patients until approximately 60% ofpatients showed unacceptable Grade III or IV toxicity in any category.Doses that are ⅔ of this value are defined as the safe dose.

Physical examination, tumor measurements, and laboratory tests should,of course, be performed before treatment and at intervals up to 1 monthlater. Laboratory tests should include complete blood counts, serumcreatinine, creatine kinase, electrolytes, urea, nitrogen, SGOT,bilirubin, albumin, and total serum protein. Serum samples taken up to60 days after treatment should be evaluated by radioimmunoassay for thepresence of the administered construct, and antibodies against anyportions thereof. Immunological analyses of sera, using any standardassay such as, for example, an ELISA or RIA, will allow thepharmacokinetics and clearance of the therapeutics to be evaluated.

To evaluate the anti-tumor responses, the patients should be examined at48 hours to 1 week and again at 30 days after the last infusion. Whenpalpable disease was present, two perpendicular diameters of all massesshould be measured daily during treatment, within 1 week aftercompletion of therapy, and at 30 days. To measure nonpalpable disease,serial CT scans could be performed at 1-cm intervals throughout thechest, abdomen, and pelvis at 48 hours to 1 week and again at 30 days.Tissue samples should also be evaluated histologically, and/or by flowcytometry, using biopsies from the disease sites or even blood or fluidsamples if appropriate.

Clinical responses may be defined by acceptable measure. For example, acomplete response may be defined by the disappearance of all measurabletumor 1 month after treatment. Whereas a partial response may be definedby a 50% or greater reduction of the sum of the products ofperpendicular diameters of all evaluable tumor nodules 1 month aftertreatment, with no tumor sites showing enlargement. Similarly, a mixedresponse may be defined by a reduction of the product of perpendiculardiameters of all measurable lesions by 50% or greater 1 month aftertreatment, with progression in one or more sites.

In light of results from clinical trials, such as those described above,an even more precise treatment regimen may be formulated. Even so, somevariation in dosage may later be necessary depending on the condition ofthe subject being treated. The physician responsible for administrationwill, in light of the present disclosure, be able to determine theappropriate dose for the individual subject. Such optimization andadjustment is routinely carried out in the art, and by no means reflectsan undue amount of experimentation.

N. Combination Tumor Therapies

The treatment methods of the present invention may be combined with anyother methods generally employed in the treatment of the particulartumor, disease or disorder that the patient exhibits. So long as aparticular therapeutic approach is not known to be detrimental to thepatient's condition in itself, and does not significantly counteract theanti-aminophospholipid or anti-anionic phospholipid-based treatment ofthe invention, its combination with the present invention iscontemplated.

Combination therapy for non malignant diseases is also contemplated. Aparticular example of such is benign prostatic hyperplasia (BPH), whichmay be treated in combination other treatments currently practiced inthe art. For example, targeting of immunotoxins to markers localizedwithin BPH, such as PSA.

In connection solid tumor treatment, the present invention may be usedin combination with classical approaches, such as surgery, chemotherapy,radiotherapy, cytokine therapy, anti-angiogenesis and the like. Theinvention therefore provides combined therapies in which the antibodies,immunoconjugates or peptide conjugates are used simultaneously with,before, or after surgery or radiation treatment; or are administered topatients with, before, or after conventional chemotherapeutic orradiotherapeutic agents, cytokines, anti-angiogenic agents,apoptosis-inducing agents, targeted immunotoxins or coaguligands or suchlike. Many examples of suitable therapeutic agents have been describedabove in connection with the immunoconjugate aspects of the presentinvention. Any of the agents initially described for use as one part ofa therapeutic conjugate may also be used separately, in the combinationtherapies of the present invention.

In terms of surgery, any surgical intervention may be practiced incombination with the present invention. In connection with radiotherapy,any mechanism for inducing DNA damage locally within tumor cells iscontemplated, such as γ-irradiation, X-rays, UV-irradiation, microwavesand even electronic emissions and the like. The directed delivery ofradioisotopes to tumor cells is also contemplated, and this may be usedin connection with a targeting antibody or other targeting means.

The general use of combinations of substances in cancer treatment iswell known. For example, U.S. Pat. No. 5,710,134 (incorporated herein byreference) discloses components that induce necrosis in tumors incombination with non-toxic substances or “prodrugs”. The enzymes setfree by necrotic processes cleave the non-toxic “prodrug” into the toxic“drug”, which leads to tumor cell death. Also, U.S. Pat. No. 5,747,469(incorporated herein by reference) discloses the combined use of viralvectors encoding p53 and DNA damaging agents. Any such similarapproaches can be used with the present invention.

When one or more agents are used in combination with the antibodies,immunoconjugates and peptide-based therapeutics of the presentinvention, there is no requirement for the combined results to beadditive of the effects observed when each treatment is conductedseparately. Although at least additive effects are generally desirable,any increased anti-tumor effect above one of the single therapies wouldbe of benefit. Also, there is no particular requirement for the combinedtreatment to exhibit synergistic effects, although this is certainlypossible and advantageous.

N1. Selection of Second Anti-Cancer Agents

The “primary therapeutic agents” of the present invention, as usedherein, are anti-aminophospholipid or anti-anionic phospholipidantibodies, immunoconjugates or PE-binding peptide derivatives andconjugates. The “secondary therapeutic agents”, as used herein, aresecond, distinct therapeutic agents or anti-cancer agents, i.e.,therapeutic agents or anti-cancer agents “other than” the primarytherapeutic agent. Any secondary therapeutic agent may be used in thecombination therapies of the present invention. Also, secondarytherapeutic agents or “second anti-cancer agents” may be selected with aview to achieving additive, greater than additive and potentiallysynergistic effects, according to the following guidance.

To practice combined anti-tumor therapy, one would simply administer toan animal or patient an anti-aminophospholipid or anti-anionicphospholipid antibody, immunoconjugate or PE-binding peptide-basedtherapeutic of the present invention in combination with another, i.e.,a second, distinct anti-cancer agent in a manner effective to result intheir combined anti-tumor actions within the animal or patient. Theagents would therefore be provided in amounts effective and for periodsof time effective to result in their combined presence within the tumoror tumor vasculature and their combined actions in the tumorenvironment. To achieve this goal, the primary therapeutics of thepresent invention and the second, distinct anti-cancer agents may beadministered to the animal substantially simultaneously, either in asingle composition, or as two distinct compositions using differentadministration routes.

Alternatively, the anti-aminophospholipid or anti-anionic phospholipidantibody, immunoconjugate or PE-binding peptide-based therapeutic of thepresent invention may precede, or follow, the second, distinctanti-cancer agent by, e.g., intervals ranging from minutes to weeks. Incertain embodiments where the primary therapeutics of the presentinvention and the second, distinct anti-cancer agents are appliedseparately to the animal, one would ensure that a significant period oftime did not expire between the time of each delivery, such that eachagent would still be able to exert an advantageously combined effect onthe tumor. In such instances, it is contemplated that one would contactthe tumor with both agents within about 5 minutes to about one week ofeach other and, more preferably, within about 12-72 hours of each other,with a delay time of only about 12-48 hours being most preferred.

The secondary therapeutic agents for separately timed combinationtherapies may be selected based upon certain criteria, including thosediscussed below. However, a preference for selecting one or more second,distinct anti-cancer agents for prior or subsequent administration doesnot preclude their use in substantially simultaneous administration ifdesired.

Second, distinct anti-cancer agents selected for administration “priorto” the primary therapeutic agents of the present invention, anddesigned to achieve increased and potentially synergistic effects,include agents that induce the expression of aminophospholipids oranionic phospholipids within the tumor vasculature. For example, agentsthat stimulate localized calcium production, activate membranetransporters that move PS and other phospholipids to the outer surfaceof the plasma membrane, injure the tumor endothelium, cause preapoptoticchanges and/or induce apoptosis in the tumor endothelium will generallyresult in increased aminophospholipid and anionic phospholipidexpression. Examples of such agents are docetaxel and paclitaxol. Theaminophospholipids and anionic phospholipids can then be targeted usingan antibody of the invention, thus amplifying the overall therapeuticeffect, and also giving increased attack via host effectors (complement,ADCC, antibody-mediated phagocytosis, CDC).

Drugs that have selectivity for angiogenic, remodeling or activatedendothelial cells, such as are present in tumor blood vessels, but notin normal resting blood vessels, can also be used to selectively causesexposure of PS and other phospholipids on the surface of tumorendothelial cells. Examples of such agents are combretastatins anddocetaxel. This again would lead to increased antibody binding andenhanced initiation of host effector mechanisms.

Second, distinct anti-cancer agents selected for administration“subsequent to” the primary therapeutic agents of the present invention,and designed to achieve increased and potentially synergistic effects,include agents that benefit from the effects of the primary therapeuticagent. The anti-aminophospholipid or anti-anionic phospholipid antibody,immunoconjugate or peptide-based therapeutic of the present inventionwill cause tumor destruction. Accordingly, effective second, distinctanti-cancer agents for subsequent administration include anti-angiogenicagents, which inhibit metastasis; agents targeting necrotic tumor cells,such as antibodies specific for intracellular antigens that becomeaccessible from malignant cells in vivo (U.S. Pat. Nos. 5,019,368,4,861,581 and 5,882,626, each specifically incorporated herein byreference); and chemotherapeutic agents and anti-tumor cellimmunoconjugates, which attack any tumor cells that may survive at theperiphery.

In some situations, it may be desirable to extend the time period fortreatment significantly, where several days (2, 3, 4, 5, 6 or 7),several weeks (1, 2, 3, 4, 5, 6, 7 or 8) or even several months (1, 2,3, 4, 5, 6, 7 or 8) lapse between the respective administrations. Thiswould be advantageous in circumstances where one treatment was intendedto substantially destroy the tumor, such as the primary therapeuticagent of the present invention, and another treatment was intended toprevent micrometastasis or tumor re-growth, such as the administrationof an anti-angiogenic agent. Anti-angiogenics should be administered ata careful time after surgery, however, to allow effective wound healing.Anti-angiogenic agents may then be administered for the lifetime of thepatient.

It is also envisioned that more than one administration of either theprimary therapeutic agent or the second, distinct anti-cancer agent willbe utilized. The primary therapeutic agent and the second, distinctanti-cancer agent may be administered interchangeably, on alternate daysor weeks; or a sequence of one agent treatment may be given, followed bya sequence of the other treatment. In any event, to achieve tumorregression using a combined therapy, all that is required is to deliverboth agents in a combined amount effective to exert an anti-tumoreffect, irrespective of the times for administration.

Whether administered substantially simultaneously or sequentially, theanti-aminophospholipid and anti-anionic phospholipid antibodies andtherapeutics of the present invention may be administered in combinationwith one or more chemotherapeutic agents or drugs. Chemotherapeuticdrugs can kill proliferating tumor cells enhancing the necrotic areascreated by the overall treatment. The drugs can thus enhance thethrombotic action of the primary therapeutic agents of the invention.

Most cancer chemotherapeutic drugs are selective for dividing,oxygenated cells. These have advantages in combined therapy as thechemotherapeutic drug acts on different targets from the primarytherapeutic agents of the invention, leading to a more completeanti-vascular or anti-tumor effect. For example, chemotherapeutic drugsare selectively active against the rapidly dividing, oxygenated tumorcells in the tumor periphery, whereas the agents of the invention actprimarily on vessels or tumor cells in the ‘stressed’ tumor core, whereactivating reactive oxygen species are abundant. Anti-angiogenic drugsthat are selective for well-oxygenated, angiogenic vessels in the tumorperiphery would also be effective in combination, as the agents of theinvention act on the relatively hypoxic, quiescent vessels in the tumorcore.

By inducing the formation of thrombi in tumor vessels, the primarytherapeutic agents of the present invention can also enhance the actionof the chemotherapeutic drugs by retaining or trapping the drugs withinthe tumor. The chemotherapeutics are thus retained within the tumor,while the rest of the drug is cleared from the body. Tumor cells arethus exposed to a higher concentration of drug for a longer period oftime. This entrapment of drug within the tumor makes it possible toreduce the dose of drug, making the treatment safer as well as moreeffective.

Further drugs for combined use in the present invention are those thatact on cells that are “sensitized” to the drug by the action of theprimary therapeutic agent, such that reduced doses of the second drugare needed to achieve its anti-tumor effect. For example, this couldoccur where a major component of the second drug's action is exerted ontumor vessels and the antibodies or agents of the invention sensitizethe cells to the drug. The same is true where the primary therapeuticagent of the invention sensitizes tumor cells to a second drug, eitherdirectly or through stimulation of cytokine release.

Other suitable second anti-cancer agents for combination therapy arethose that enhance the activity of host effector cells, e.g., byselectively inhibiting the activity of immunosuppressive components ofthe immune system. Such agents enable the primary therapeutic agents ofthe invention, which stimulate attack by effector cells as part of theirmechanism, to work more aggressively. An example of such an agent isdocetaxel.

Although an understanding of the precise mechanism(s) of action of theprimary therapeutic agents is not necessary to practice the treatment ofthe invention, data and reasoned deductions concerning such mechanismscan be used to select particular second anti-cancer agents for combineduse in the present invention. The effectiveness of the chosencombination therapy, in turn, supports the original data and proposedmechanisms of action, and also leads to preferred categories of secondanti-cancer agents for practicing combination therapy.

Drugs that induce apoptosis are preferred for use in the combinationtherapies. Docetaxel, for example, induces apoptosis and therefore PSexposure by binding to microtubules and disrupting cell mitosis(Hotchkiss et al., 2002). Treatment of endothelial cells, which linetumor blood vessels, and tumor cells with docetaxel at subclinicalconcentrations is herein shown to induce PS expression at the cellsurface, as demonstrated by strong binding of the 3G4 antibody in vitro.

The present inventors have also determined that the anti-tumor effectsof the antibodies of the invention include Fc domain-mediatedaugmentation of immune effector functions, as shown by increasedantibody-mediated phagocytosis. Therefore, the antibodies should alsoexert other Fc domain-mediated functions, such as ADCC, CDC, stimulationof cytokine production, and such mechanisms in combination. This is alsorelevant to docetaxel, as other studies have shown that the treatment ofbreast cancer patients with docetaxel leads to increases in serum IFN-γ,IL-2, IL-6 and GM-CSF cytokine levels, augmenting the anti-tumor immuneresponses in these patients by enhancing the activity of natural killer(NK) and lymphokine activated killer (LAK) cells (Tsavaris et al.,2002).

Therefore, the inventors reasoned that docetaxel will both induce PSexpression and binding of the administered antibody, and also enhancesthe activities of immune effectors, which mediate anti-tumor effects.Based upon the foregoing considerations, the inventors have shown thatcombination of the antibodies of the present invention, as exemplifiedby the 3G4 antibody, with docetaxel was significantly superior to eitherdocetaxel or 3G4 alone in mice bearing orthotopic MDA-MB-435 humanbreast cancer xenografts (Example XX).

Accordingly, docetaxel and other chemotherapeutic agents that induceapoptosis are preferred agents for use in the combination treatments ofthe present invention. Combinations of antibodies to aminophospholipidsand/or anionic phospholipids with chemotherapeutics drugs that induceapoptosis, such as docetaxel, should synergistically attack tumorvasculature endothelial cell and tumor cell compartments, leading to notonly significantly enhanced treatment efficacy but also lower toxicity.These combinations are contemplated for use in breast cancer treatment,particularly the combination of metronomic chemotherapy using docetaxelwith an antibody of the present invention.

N2. Endotoxin

Endotoxin and detoxified endotoxin derivatives may be used in thecombination treatment, preferably at low doses (PCT Publication No. WO03/028840, specifically incorporated herein by reference). Variousdetoxified endotoxins are available, which are preferred for use inanimals and particularly for use in humans. Detoxified and refinedendotoxins, and combinations thereof, are described in U.S. Pat. Nos.4,866,034; 4,435,386; 4,505,899; 4,436,727; 4,436,728; 4,505,900, eachspecifically incorporated herein by reference.

The non-toxic derivative monophosphoryl lipid A (MPL) is one example ofa detoxified endotoxin that may be used in the present invention. MPL isknown to be safe for humans; clinical trials using MPL as an adjuvanthave shown 100 μg/m² to be safe for human use, even on an outpatientbasis.

N3. Cytokines

Cytokine therapy has proven to be an effective partner for combinedtherapeutic regimens. Various cytokines may be employed in the combinedapproaches of the present invention. Examples of cytokines include IL-1αIL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11,IL-12, IL-13, TGF-β, GM-CSF, M-CSF, G-CSF, TNFα, TNFβ, LAF, TCGF, BCGF,TRF, BAF, BDG, MP, LIF, OSM, TMF, PDGF, IFN-α, IFN-β, IFN-γ. Cytokinesare administered according to standard regimens, consistent withclinical indications such as the condition of the patient and relativetoxicity of the cytokine. Uteroglobins may also be used to prevent orinhibit metastases (U.S. Pat. No. 5,696,092; incorporated herein byreference).

N4. TNFα and Inducers of TNFα

TNFα and inducers of TNFα may also be used in combination with thepresent invention. TNFα increases vascular permeability, and istherefore useful in facilitating the penetration of anti-cancer agentsinto the tumor. Although antibody localization is by no means a problemwhen targeting aminophospholipid and anionic phospholipids, as in thepresent invention, the combined use of TNFα can facilitate access ofother chemotherapeutics and immunoconjugates to the tumor, and evenincrease binding of the antibodies of the invention to far distant tumorcells.

Low levels of endotoxin, Rac1 antagonists, such as an attenuated orengineered adenovirus, DMXAA (and FAA), CM101 and thalidomide may alsobe used. Rac1 antagonists may be used in the combined treatment of thepresent invention, as about 5000 DNA particles per cell cause TNFupregulation independent of CD14 (Sanlioglu et al., 2001). CM101,thalidomide and DMXAA can also be used in combination herewith, atstandard or reduced doses.

N5. Chemotherapeutics

Irrespective of the underlying mechanism(s), a variety ofchemotherapeutic agents may be used in the combined treatment methodsdisclosed herein. Chemotherapeutic agents contemplated for combined useinclude, e.g., tamoxifen, taxol, vinblastine, etoposide (VP-16),adriamycin, 5-fluorouracil (5FU), camptothecin, actinomycin-D, mitomycinC, combretastatin(s), more particularly docetaxel (taxotere), cisplatin(CDDP), cyclophosphamide, doxorubicin, methotrexate, paclitaxel andvincristine, and derivatives and prodrugs thereof.

As will be understood by those of ordinary skill in the art, appropriatedoses of chemotherapeutic agents include those already employed inclinical therapies wherein the chemotherapeutics are administered aloneor in combination with other chemotherapeutics. However, lower doses arenow possible due to the advantages provided by the present invention. Byway of example only, agents such as cisplatin, and other DNA alkylatingmay be used. Cisplatin has been widely used to treat cancer, withefficacious doses used in clinical applications of 20 mg/m² for 5 daysevery three weeks for a total of three courses. Cisplatin is notabsorbed orally and must therefore be delivered via injectionintravenously, subcutaneously, intratumorally or intraperitoneally.

Further useful agents include compounds that interfere with DNAreplication, mitosis, chromosomal segregation and/or tubulin activity.Such chemotherapeutic compounds include adriamycin, also known asdoxorubicin, etoposide, verapamil, podophyllotoxin(s), combretastatin(s)and the like. Widely used in a clinical setting for the treatment ofneoplasms, these compounds are administered through bolus injectionsintravenously at doses ranging from 25-75 mg/m² at 21 day intervals foradriamycin, to 35-50 mg/m² for etoposide intravenously or double theintravenous dose orally.

Agents that disrupt the synthesis and fidelity of polynucleotideprecursors may also be used. Particularly useful are agents that haveundergone extensive testing and are readily available. As such, agentssuch as 5-fluorouracil (5-FU) are preferentially used by neoplastictissue, making this agent particularly useful for targeting toneoplastic cells. Although quite toxic, 5-FU, is applicable in a widerange of carriers, including topical, however intravenous administrationwith doses ranging from 3 to 15 mg/kg/day being commonly used.

Exemplary chemotherapeutic agents that are useful in connection withcombined therapy are listed in Table D. Each of the agents listedtherein are exemplary and by no means limiting. The skilled artisan isdirected to “Remington's Pharmaceutical Sciences” 15th Edition, chapter33, in particular pages 624-652. Some variation in dosage willnecessarily occur depending on the condition of the subject beingtreated. The physician responsible for administration will be able todetermine the appropriate dose for the individual subject.

TABLE D CHEMOTHERAPEUTIC AGENTS USEFUL IN NEOPLASTIC DISEASENONPROPRIETARY TYPE OF NAMES CLASS AGENT (OTHER NAMES) DISEASEAlkylating Nitrogen Mechlorethamine (HN₂) Hodgkin's disease,non-Hodgkin's lymphomas Agents Mustards Cyclophosphamide Acute andchronic lymphocytic leukemias, Ifosfamide Hodgkin's disease,non-Hodgkin's lymphomas, multiple myeloma, neuroblastoma, breast, ovary,lung, Wilms' tumor, cervix, testis, soft-tissue sarcomas MelphalanMultiple myeloma, breast, ovary (L-sarcolysin) Chlorambucil Chroniclymphocytic leukemia, primary macroglobulinemia, Hodgkin's disease,non-Hodgkin's lymphomas Ethylenimenes Hexamethylmelamine Ovary andMethylmelamines Thiotepa Bladder, breast, ovary Alkyl SulfonatesBusulfan Chronic granulocytic leukemia Nitrosoureas Carmustine (BCNU)Hodgkin's disease, non-Hodgkin's lymphomas, primary brain tumors,multiple myeloma, malignant melanoma Lomustine (CCNU) Hodgkin's disease,non-Hodgkin's lymphomas, primary brain tumors, small-cell lung Semustine(methyl-CCNU) Primary brain tumors, stomach, colon StreptozocinMalignant pancreatic insulinoma, (streptozotocin) malignant carcinoidTriazines Dacarbazine (DTIC; Malignant melanoma, Hodgkin's disease,dimethyltriazeno- soft-tissue sarcomas imidazolecarboxamide)Antimetabolites Folic Acid Methotrexate Acute lymphocytic leukemia,choriocarcinoma, Analogs (amethopterin) mycosis fungoides, breast, headand neck, lung, osteogenic sarcoma Pyrimidine Fluouracil Breast, colon,stomach, pancreas, ovary, Analogs (5-fluorouracil; 5-FU) head and neck,urinary bladder, Floxuridine premalignant skin lesions (topical)(fluorodeoxyuridine; FUdR) Cytarabine Acute granulocytic and acute(cytosine arabinoside) lymphocytic leukemias Mercaptopurine Acutelymphocytic, acute granulocytic and (6-mercaptopurine; 6-MP) chronicgranulocytic leukemias Purine Analogs and Thioguanine Acutegranulocytic, acute lymphocytic and Related Inhibitors (6-thioguanine;TG) chronic granulocytic leukemias Pentostatin Hairy cell leukemia,mycosis fungoides, (2-deoxycoformycin) chronic lymphocytic leukemiaNatural Vinca Alkaloids Vinblastine (VLB) Hodgkin's disease,non-Hodgkin's lymphomas, Products breast, testis Vincristine Acutelymphocytic leukemia, neuroblastoma, Wilms' tumor, rhabdomyosarcoma,Hodgkin's disease, non-Hodgkin's lymphomas, small-cell lungEpipodophyllotoxins Etoposide Testis, small-cell lung and other lung,Tertiposide breast, Hodgkin's disease, non-Hodgkin's lymphomas, acutegranulocytic leukemia, Kaposi's sarcoma Antibiotics DactinomycinChoriocarcinoma, Wilms' tumor, (actinomycin D) rhabdomyosarcoma, testis,Kaposi's sarcoma Daunorubicin Acute granulocytic and acute (daunomycin;lymphocytic leukemias rubidomycin) Doxorubicin Soft-tissue, osteogenicand other sarcomas; Hodgkin's disease, non-Hodgkin's lymphomas, acuteleukemias, breast, genitourinary, thyroid, lung, stomach, neuroblastomaBleomycin Testis, head and neck, skin, esophagus, lung and genitourinarytract; Hodgkin's disease, non-Hodgkin's lymphomas Plicamycin Testis,malignant hypercalcemia (mithramycin) Mitomycin Stomach, cervix, colon,breast, pancreas, (mitomycin C) bladder, head and neck EnzymesL-Asparaginase Acute lymphocytic leukemia Biological Interferon alfaHairy cell leukemia., Kaposi's sarcoma, Response melanoma, carcinoid,renal cell, ovary, Modifiers bladder, non-Hodgkin's lymphomas, mycosisfungoides, multiple myeloma, chronic granulocytic leukemia MiscellaneousPlatinum Cisplatin (cis-DDP) Testis, ovary, bladder, head and neck,Agents Coordination Carboplatin lung, thyroid, cervix, endometrium,Complexes neuroblastoma, osteogenic sarcoma Anthracenedione MitoxantroneAcute granulocytic leukemia, breast Substituted Urea Hydroxyurea Chronicgranulocytic leukemia, polycythemia vera, essental thrombocytosis,malignant melanoma Methyl Hydrazine Procarbazine Hodgkin's diseaseDerivative (N-methylhydrazine, MlH) Adrenocortical Mitotane (o,p′-DDD)Adrenal cortex Suppressant Aminoglutethimide Breast Hormones andAdrenocortico- Prednisone (several other Acute and chronic lymphocyticleukemias, Antagonists steroids equivalent preparations non-Hodgkin'slymphomas, Hodgkin's available) disease, breast ProgestinsHydroxyprogesterone Endometrium, breast caproate Medroxyprogesteroneacetate Megestrol acetate Estrogens Diethylstilbestrol Breast, prostateEthinyl estradiol (other preparations available) Antiestrogen TamoxifenBreast Androgens Testosterone propionate Breast Fluoxymesterone (otherpreparations available) Antiandrogen Flutamide ProstateGonadotropin-releasing Leuprolide Prostate hormone analog

N6. Anti-Angiogenics

The term “angiogenesis” refers to the generation of new blood vessels,generally into a tissue or organ. Under normal physiological conditions,humans or animals undergo angiogenesis only in specific restrictedsituations. For example, angiogenesis is normally observed in woundhealing, fetal and embryonic development and formation of the corpusluteum, endometrium and placenta. New evidence, however, shows thatangiogenesis is important in certain normal situations, such as inadrenal tissue, prostate and ovary. The therapeutic agents of thepresent invention, in which anti-angiogenesis is not the only mode ofaction, thus have advantages over prominent anti-angiogenic therapies,such as antibody A4.6.1 (Brem, 1998; Baca et al., 1997; Presta et al.,1997), in that desirable or “physiological” angiogenesis will not beinhibited when using the present invention.

Uncontrolled (persistent and/or unregulated) angiogenesis is related tovarious disease states, and occurs during tumor development andmetastasis. Both controlled and uncontrolled angiogenesis are thought toproceed in a similar manner. Endothelial cells and pericytes, surroundedby a basement membrane, form capillary blood vessels. Angiogenesisbegins with the erosion of the basement membrane by enzymes released byendothelial cells and leukocytes. The endothelial cells, which line thelumen of blood vessels, then protrude through the basement membrane.Angiogenic stimulants induce the endothelial cells to migrate throughthe eroded basement membrane. The migrating cells form a “sprout” offthe parent blood vessel, where the endothelial cells undergo mitosis andproliferate. The endothelial sprouts merge with each other to formcapillary loops, creating the new blood vessel.

Despite the new evidence that angiogenesis is required in some normaltissues, anti-angiogenic therapies are still important in the treatmentof tumors and other diseases. Anti-angiogenic therapies are thereforeintended for use in the combination treatments of the present invention.The combination of a low, relatively frequent dose of a therapeuticagent of the present invention in combination with an agent thatinhibits angiogenesis is particularly contemplated. Exemplaryanti-angiogenic agents that are useful in connection with combinedtherapy are listed above (in connection with immunoconjugates). Any oneor more of such agents, including those in Table B, may be used incombination therapy with the invention. Angiostatin, endostatin,vasculostatin, canstatin and maspin are currently preferred.

Many known anti-cancer agents also have an anti-angiogenic effect aspart of their mechanism of action. These agents, as exemplified by thosein Table E, are particularly contemplated for use in the combinationtherapy aspects of the present invention (they may also be conjugated toan antibody of the invention, as described above).

TABLE E Anti-Cancer Agents with Anti-Angiogenic Activity Class or Typeof Agent Examples Alkylators Cyclophosphamide, edelfosine, estramustine,melphalan Antimetabolites Fluorouracil, methotrexate, mercaptopurine,UFT, tegafur, uracil, cytarabine Anti-Tumor Bleomycin, daunorubicin,doxorubicin, epirubicin, Antibiotics mitomycin, mitoxantroneTopoisomerase Camptothecin, irinotecan, etoposide, topotecan InhibitorsTaxanes Docetaxel, paclitxael Vinca Alkaloids Vinblastine, vincristineMiscellaneous Cisplatin, octreotide

In addition, the antibody LM609 against the α_(v)β₃ integrin alsoinduces tumor regressions and may be used in combination therapies.Integrin α_(v)β₃ antagonists, such as LM609, induce apoptosis ofangiogenic endothelial cells leaving the quiescent blood vesselsunaffected. LM609 or other α_(v)β₃ antagonists may also work byinhibiting the interaction of α_(v)β₃ and MMP-2, a proteolytic enzymethought to play an important role in migration of endothelial cells andfibroblasts.

Apoptosis of the angiogenic endothelium by LM609 may have a cascadeeffect on the rest of the vascular network. Inhibiting the tumorvascular network from completely responding to the tumor's signal toexpand may, in fact, initiate the partial or full collapse of thenetwork resulting in tumor cell death and loss of tumor volume. It ispossible that endostatin and angiostatin function in a similar fashion.The fact that LM609 does not affect quiescent vessels but is able tocause tumor regressions suggests strongly that not all blood vessels ina tumor need to be targeted for treatment in order to obtain ananti-tumor effect.

Antibodies to angiogenin may also be employed, as described in U.S. Pat.No. 5,520,914, specifically incorporated herein by reference. As FGF isconnected with angiogenesis, FGF inhibitors may also be used. Certainexamples are the compounds having N-acetylglucosamine alternating insequence with 2-O-sulfated uronic acid as their major repeating units,including glycosaminoglycans, such as archaran sulfate. Such compoundsare described in U.S. Pat. No. 6,028,061, specifically incorporatedherein by reference, and may be used in combination herewith.

N7. VEGF Inhibitors

VEGF is a multifunctional cytokine that is induced by hypoxia andoncogenic mutations. VEGF is a primary stimulant of the development andmaintenance of a vascular network in embryogenesis. It functions as apotent permeability-inducing agent, an endothelial cell chemotacticagent, an endothelial survival factor, and endothelial cellproliferation factor. Its activity is required for normal embryonicdevelopment, as targeted disruption of one or both alleles of VEGFresults in embryonic lethality.

The use of one or more VEGF inhibition methods is a preferred aspect ofthe combination therapies of the present invention. The recognition ofVEGF as a primary stimulus of angiogenesis in pathological conditionshas led to various methods to block VEGF activity. Any of the VEGFinhibitors developed may now be advantageously employed herewith.Accordingly, any one or more of the following neutralizing anti-VEGFantibodies, soluble receptor constructs, antisense strategies, RNAaptamers and tyrosine kinase inhibitors designed to interfere with VEGFsignaling may thus be used.

Suitable agents include neutralizing antibodies (Kim et al., 1992;Presta et al., 1997; Sioussat et al., 1993; Kondo et al., 1993; Asano etal., 1995), soluble receptor constructs (Kendall and Thomas, 1993;Aiello et al., 1995; Lin et al., 1998; Millauer et al., 1996), tyrosinekinase inhibitors (Siemeister et al., 1998), antisense strategies, RNAaptamers and ribozymes against VEGF or VEGF receptors (Saleh et al.,1996; Cheng et al., 1996). Variants of VEGF with antagonistic propertiesmay also be employed, as described in WO 98/16551. Each of the foregoingreferences are specifically incorporated herein by reference.

Blocking antibodies against VEGF will be preferred in certainembodiments, particularly for simplicity. Monoclonal antibodies againstVEGF have been shown to inhibit human tumor xenograft growth and ascitesformation in mice (Kim et al., 1993; Mesiano et al., 1998; Luo et al.,1998a; 1998b; Borgstrom et al., 1996; 1998; each incorporated herein byreference). The antibody A4.6.1 is a high affinity anti-VEGF antibodycapable of blocking VEGF binding to both VEGFR1 and VEGFR2 (Kim et al.,1992; Wiesmann et al., 1997; Muller et al., 1998; Keyt et al., 1996;each incorporated herein by reference). A4.6.1 has recently beenhumanized by monovalent phage display techniques and is currently inPhase I clinical trials as an anti-cancer agent (Brem, 1998; Baca etal., 1997; Presta et al., 1997; each incorporated herein by reference).

Alanine scanning mutagenesis and X-ray crystallography of VEGF bound bythe Fab fragment of A4.6.1 showed that the epitope on VEGF that A4.6.1binds is centered around amino acids 89-94. This structural datademonstrates that A4.6.1 competitively inhibits VEGF from binding toVEGFR2, but inhibits VEGF from binding to VEGFR1 most likely by sterichindrance (Muller et al., 1998; Keyt et al, 1996; each incorporatedherein by reference).

A4.6.1 may be used in combination with the present invention. However, anew antibody termed 2C3 (4545) is currently preferred, which selectivelyblocks the interaction of VEGF with only one of the two VEGF receptors.2C3 inhibits VEGF-mediated growth of endothelial cells, has potentanti-tumor activity and selectively blocks the interaction of VEGF withVEGFR2 (KDR/Flk-1), but not VEGFR1 (FLT-1). In contrast to A4.6.1, 2C3allows specific inhibition of VEGFR2-induced angiogenesis, withoutconcomitant inhibition of macrophage chemotaxis (mediated by VEGFR1),and is thus contemplated to be a safer therapeutic. U.S. Pat. Nos.6,342,219, 6,342,221, 6,416,758 and 6,416,758, are specificallyincorporated herein by reference for the purposes of even furtherdescribing the 2C3 antibody and its uses in anti-angiogenic therapy andVEGF inhibition.

N8. Apoptosis-Inducing Agents

The therapeutic agents of the present invention are also preferablycombined with treatment methods that induce apoptosis in any cellswithin the tumor, including tumor cells and tumor vascular endothelialcells. Exemplary agents that induce apoptosis are listed above (inconnection with immunoconjugates). Any one or more of suchapoptosis-inducing agents may be used in the combination therapies ofthe present invention, without being linked to an antibody of theinvention.

Many known anti-cancer agents also have an apoptosis-inducing effect aspart of their mechanism of action. These agents, as exemplified by thosein Table F, are particularly contemplated for use in the combinationtherapy aspects of the present invention (they may also be conjugated toan antibody of the invention, as described above).

TABLE F Anti-Cancer Agents that Induce Apoptosis Class or Type of AgentExamples Antimetabolites Cytarabine, fludarabine,5-fluoro-29-deoxyuridine, gemcitabine, hydroxyurea, methotrexate DNACross- Chlorambucil, cisplatin, Linking Agents cyclophosphamide,nitrogen mustard Intercalating Adriamycin (doxorubicin), Agentsmitixantrone Topoisomerase Etoposide, teniposide II Poisons Microtubule-Colcemid, colchicine, Directed Agents docetaxel, vincristine KinaseInhibitors Flavopiridol, staurosporine, STI571 (CPG 57148B), UCN-01(7-hydroxystaurosporine) Farnesyl Transferase L-739749, L-744832Inhibitors Hormones Glucocorticoids, fenretinide DNA FragmentingBleomycin Agents Hormone Antagonists Tamoxifen, finasteride, LHRHantagonists Biologicals TNF-α, TRAIL, anti-CD20 Protein SynthesisL-asparaginase, cycloheximide, Inhibitors puromycin, diphtheria toxinTopoisomerase Camptothecin, toptecan II Poisons

N9. Immunotoxins and Coaguligands

The present invention may also be used in combination with otherimmunotoxins or coaguligands in which the targeting portion is directedto a marker of tumor cells, tumor vasculature or tumor stroma. Any ofthe targeting agents described herein for use in targeting a PE-bindingpeptide to a tumor cell, tumor vasculature or tumor stroma may be usedin these embodiments. In the immunotoxins, the attached agents includeanti-cellular or cytotoxic agents, cytokines, radiotherapeutic agents,anti-angiogenic agents, apoptosis-inducing agents and anti-tubulindrugs. In the coaguligands, the attached agents are coagulants. U.S.Pat. Nos. 5,855,866, 5,965,132, 6,261,535, 6,051,230, 6,451,312(immunotoxins), 6,093,399, 6,004,555, 5,877,289, and 6,036,955(coaguligands) are specifically incorporated herein by reference toexemplify such constructs.

N10. ADEPT and Prodrug Therapy

The antibodies of the present invention, including the 9D2, 3G4 (ATCC4545) and like antibodies, may also be used in conjunction withprodrugs, wherein the antibody is operatively associated with aprodrug-activating component, such as a prodrug-activating enzyme, whichconverts a prodrug to the more active form only upon contact with theantibody. This technology is generally termed “ADEPT”, and is describedin, e.g., WO 95/13095; WO 97/26918, WO 97/24143, and U.S. Pat. Nos.4,975,278 and 5,658,568, each specifically incorporated herein byreference.

The term “prodrug”, as used herein, refers to a precursor or derivativeform of a biologically or pharmaceutically active substance that exertsreduced cytotoxic or otherwise anticellular effects on targets cells,including tumor vascular endothelial cells, in comparison to the parentdrug upon which it is based. Preferably, the prodrug or precursor formexerts significantly reduced, or more preferably, negligible, cytotoxicor anticellular effects in comparison to the “native” or parent form.“Prodrugs” are capable of being activated or converted to yield the moreactive, parent form of the drug.

The technical capability to make and use prodrugs exists within theskill of the ordinary artisan. Willman et al. (1986) and Stella et al.(1985) are each specifically incorporated herein by reference forpurposes of further supplementing the description and teachingconcerning how to make and use various prodrugs. Exemplary prodrugconstructs that may be used in the context of the present inventioninclude, but are not limited to, phosphate-containing prodrugs (U.S.Pat. No. 4,975,278), thiophosphate-containing prodrugs,sulfate-containing prodrugs, peptide-based prodrugs (U.S. Pat. Nos.5,660,829; 5,587,161; 5,405,990; WO 97/07118), D-amino acid-modifiedprodrugs, glycosylated prodrugs (U.S. Pat. Nos. 5,561,119; 5,646,298;4,904,768, 5,041,424), β-lactam-containing prodrugs, optionallysubstituted phenoxyacetamide-containing prodrugs (U.S. Pat. No.4,975,278), optionally substituted phenylacetamide-containing prodrugs,and even 5-fluorocytosine (U.S. Pat. No. 4,975,278) and 5-fluorouridineprodrugs and the like, wherein each of the patents are specificallyincorporated herein by reference.

The type of therapeutic agent or cytotoxic drug that can be used inprodrug form is virtually limitless. The more cytotoxic agents will bepreferred for such a form of delivery, over, e.g., the delivery ofcoagulants, which are less preferred for use as prodrugs. All that isrequired in forming the prodrug is to design the construct so that theprodrug is substantially inactive and the “released” or activated drughas substantial, or at least sufficient, activity for the intendedpurpose.

Various improvements on the original prodrugs are also known andcontemplated for use herewith, as disclosed in WO 95/03830; EP 751,144(anthracyclines); WO 97/07097 (cyclopropylindoles); and WO 96/20169. Forexample, prodrugs with reduced Km are described in U.S. Pat. No.5,621,002, specifically incorporated herein by reference, which may beused in the context of the present invention. Prodrug therapy that beconducted intracellularly is also known, as exemplified by WO 96/03151,specifically incorporated herein by reference, and can be practicedherewith.

For use in ADEPT, the agent that activates or converts the prodrug intothe more active drug is operatively attached to an antibody of theinvention. The antibody thus localizes the prodrug converting capabilitywithin the angiogenic or tumor site, so that active drug is onlyproduced in such regions and not in circulation or in healthy tissues.

Enzymes that may be attached to the antibodies of the invention tofunction in prodrug activation include, but are not limited to, alkalinephosphatase for use in combination with phosphate-containing prodrugs(U.S. Pat. No. 4,975,278); arylsulfatase for use in combination withsulfate-containing prodrugs (U.S. Pat. No. 5,270,196); peptidases andproteases, such as serratia protease, thermolysin, subtilisin,carboxypeptidase (U.S. Pat. Nos. 5,660,829; 5,587,161; 5,405,990) andcathepsins (including cathepsin B and L), for use in combination withpeptide-based prodrugs; D-alanylcarboxypeptidases for use in combinationwith D-amino acid-modified prodrugs; carbohydrate-cleaving enzymes suchas β-galactosidase and neuramidase for use in combination withglycosylated prodrugs (U.S. Pat. Nos. 5,561,119; 5,646,298); β-lactamasefor use in combination with β-lactam-containing prodrugs; penicillinamidases, such as penicillin V amidase (U.S. Pat. No. 4,975,278) orpenicillin G amidase, for use in combination with drugs derivatized attheir amino nitrogens with phenoxyacetamide or phenylacetamide groups;and cytosine deaminase (U.S. Pat. Nos. 5,338,678; 5,545,548) for use incombination with 5-fluorocytosine-based prodrugs (U.S. Pat. No.4,975,278), wherein each of the patents are specifically incorporatedherein by reference.

Antibodies with enzymatic activity, known as catalytic antibodies or“abzymes”, can also be employed to convert prodrugs into active drugs.Abzymes based upon the antibodies of the invention, preferably the 9D2and 3G4 and like antibodies, thus form another aspect of the presentinvention. The technical capacity to make abzymes also exists withinthose of ordinary skill in the art, as exemplified by Massey et al.(1987), specifically incorporated herein by reference for purposes ofsupplementing the abzyme teaching. Catalytic antibodies capable ofcatalyzing the breakdown of a prodrug at the carbamate position, such asa nitrogen mustard aryl carbamate, are further contemplated, asdescribed in EP 745,673, specifically incorporated herein by reference.

O. Antibody-Coated Liposomes and Therapeutics

Liposomal formulations are often used in therapeutics andpharmaceuticals. However, the biodistribution of liposomes in initialstudies meant that such formulations were not widely applicable for usein humans. Liposomes are rapidly taken up by the phagocytic cells of thereticuloendothelial system (RES), including the circulating mononuclearphagocytic cells and those located in the liver and spleen. Thus, theblood circulation half-lives can be as short as a few minutes.

The technology of “stealth or stealthed” liposomes and formulations wasthus developed, which allows liposomes to evade uptake by the RES andcirculate for longer (Hristova and Needham, 1993). A preferred agent foruse in stealthing liposomes is polyethylene glycol (PEG), and theresultant liposomes are also termed PEGylated liposomes. Otherstealthing agents include poly(2-methyl-2-oxazoline) andpoly(2-ethyl-2-oxazoline) conjugates (Woodle et al., 1994). A range ofimproved stealthed liposomes are described in U.S. Pat. No. 6,284,267,specifically incorporated herein by reference, which may be used incombination with the present invention.

Liposomes smaller in diameter than the average diameter of the fenestraein capillaries leak out from the circulation. The average diameter ofthe fenestrae in rapidly growing tumors is larger than in normal tissuesand therefore liposomes smaller than about 100 nm in diameter migrateinto tumors. Stealth liposomes have thus been proposed for use indelivering cytotoxic agents to tumors in cancer patients. A range ofdrugs have been incorporated into stealth liposomes, including cisplatin(Rosenthal et al., 2002), TNFα (Kim et al., 2002), doxorubicin (Symon etal., 1999) and adriamycin (Singh et al., 1999), each reference beingspecifically incorporated herein by reference. However, recent reportshave indicated unexpected low efficacy of stealth liposomal doxorubicinand vinorelbine in the treatment of metastatic breast cancer (Rimassa etal., 2003).

The present invention provides improved stealthed liposome formulations,overcoming various of the drawbacks in the art, in which the stealthedliposomes are functionally associated or “coated” with an antibody thatbinds to an aminophospholipid or anionic phospholipid, preferably to PSor PE. The 9D2, 3G4 (ATCC 4545) and like, competing antibodies of theinvention are preferred for such uses, although any antibody, or antigenbinding region thereof, which binds to an aminophospholipid or anionicphospholipid may be used. A divalent antibody or antibody portion is notrequired in these aspects of the invention.

Any stealthed liposome may form the basis of the new liposomalformulations, and preferably a PEGylated liposome will be employed. Thestealthed liposomes are “coated”, i.e., operatively or functionallyassociated with the antibody that binds to an aminophospholipid oranionic phospholipid. The operative or functional association is madesuch that the antibody retains the ability to specifically bind to thetarget aminophospholipid or anionic phospholipid, preferably PS or PE,thereby delivering or targeting the stealthed liposome and any contentsthereof to PS- and/or PE-positive cells, such as tumor cells and tumorvascular endothelial cells.

The antibody-coated stealthed liposomes of the invention may be usedalone. Preferably, however, such liposomes will also contain one or moresecond therapeutic agents, such as anti-cancer or chemotherapeuticagents (the first therapeutic agent being the antibody itself). Thesecond therapeutic agents are generally described as being within the“core” of the liposome. Any one or more of the second, anti-cancer orchemotherapeutic agents known in the art and/or described herein forconjugation to antibodies, or for combination therapies, may be used inthe antibody-coated stealthed liposomes of the invention. For example,any chemotherapeutic or radiotherapeutic agent, cytokine,anti-angiogenic agent or apoptosis-inducing agent. Currently preferredwithin the chemotherapeutic agents are anti-tubulin drugs, docetaxel andpaclitaxel.

Moreover, the antibody-coated stealthed liposomes of the invention mayalso be loaded with one or more anti-viral drugs for use in treatingviral infections and diseases. As with the anti-cancer agents, any oneor more of the second, anti-viral drugs known in the art and/ordescribed herein for conjugation to antibodies, or for combinationtherapies, may be used in the antibody-coated stealthed liposomes of theinvention. Cidofovir and AZT are currently preferred examples.

P. Anti-Vascular, Anti-Angiogenic and Other Therapies

The present invention may also be used in the treatment of otherdiseases in which aberrant vasculature is involved, including diseasesand disorders having prothrombotic blood vessels. Although not the onlytherapeutic mechanism, the antibodies, immunoconjugates andpeptide-based therapeutics of the present invention may also be used totreat animals and patients with aberrant angiogenesis, such as thatcontributing to a variety of diseases and disorders.

Whether based upon anti-angiogenesis, prothrombotic vasculature or otheranti-vascular mechanisms, the present invention may thus be used totreat prevalent and/or clinically important diseases outside the fieldof cancer, including arthritis, rheumatoid arthritis, psoriasis,atherosclerosis, diabetic retinopathy, age-related macular degeneration,Grave's disease, vascular restenosis, including restenosis followingangioplasty, arteriovenous malformations (AVM), meningioma, hemangiomaand neovascular glaucoma. Other targets for intervention includeangiofibroma, atherosclerotic plaques, corneal graft neovascularization,hemophilic joints, hypertrophic scars, osler-weber syndrome, pyogenicgranuloma retrolental fibroplasia, scleroderma, trachoma, vascularadhesions, synovitis, dermatitis, various other inflammatory diseasesand disorders, and even endometriosis. Further diseases and disordersthat are treatable by the invention, and the unifying basis of suchdisorders, are set forth below.

One prominent disease in which aberrant vasculature and angiogenesis isinvolved is rheumatoid arthritis, wherein the blood vessels in thesynovial lining of the joints undergo angiogenesis. In addition toforming new vascular networks, the endothelial cells release factors andreactive oxygen species that lead to pannus growth and cartilagedestruction. The factors involved in angiogenesis may activelycontribute to, and help maintain, the chronically inflamed state ofrheumatoid arthritis. Factors associated with angiogenesis also have arole in osteoarthritis, contributing to the destruction of the joint.Various factors, including VEGF, have been shown to be involved in thepathogenesis of rheumatoid arthritis and osteoarthritis.

Another important example of a disease involving aberrant vasculatureand angiogenesis is ocular neovascular disease. This disease ischaracterized by invasion of new blood vessels into the structures ofthe eye, such as the retina or cornea. It is the most common cause ofblindness and is involved in approximately twenty eye diseases. Inage-related macular degeneration, the associated visual problems arecaused by an ingrowth of chorioidal capillaries through defects inBruch's membrane with proliferation of fibrovascular tissue beneath theretinal pigment epithelium. Angiogenic damage is also associated withdiabetic retinopathy, retinopathy of prematurity, corneal graftrejection, neovascular glaucoma and retrolental fibroplasia.

Other diseases associated with corneal neovascularization that can betreated according to the present invention include, but are not limitedto, epidemic keratoconjunctivitis, Vitamin A deficiency, contact lensoverwear, atopic keratitis, superior limbic keratitis, pterygiumkeratitis sicca, sjogrens, acne rosacea, phylectenulosis, syphilis,Mycobacteria infections, lipid degeneration, chemical burns, bacterialulcers, fungal ulcers, Herpes simplex infections, Herpes zosterinfections, protozoan infections, Kaposi sarcoma, Mooren ulcer,Terrien's marginal degeneration, mariginal keratolysis, rheumatoidarthritis, systemic lupus, polyarteritis, trauma, Wegeners sarcoidosis,Scleritis, Steven's Johnson disease, periphigoid radial keratotomy, andcorneal graph rejection.

Diseases associated with retinal/choroidal neovascularization that canbe treated according to the present invention include, but are notlimited to, diabetic retinopathy, macular degeneration, sickle cellanemia, sarcoid, syphilis, pseudoxanthoma elasticum, Pagets disease,vein occlusion, artery occlusion, carotid obstructive disease, chronicuveitis/vitritis, mycobacterial infections, Lyme's disease, systemiclupus erythematosis, retinopathy of prematurity, Eales disease, Bechetsdisease, infections causing a retinitis or choroiditis, presumed ocularhistoplasmosis, Bests disease, myopia, optic pits, Stargarts disease,pars planitis, chronic retinal detachment, hyperviscosity syndromes,toxoplasmosis, trauma and post-laser complications.

Other diseases that can be treated according to the present inventioninclude, but are not limited to, diseases associated with rubeosis(neovascularization of the angle) and diseases caused by the abnormalproliferation of fibrovascular or fibrous tissue including all forms ofproliferative vitreoretinopathy, whether or not associated withdiabetes.

Chronic inflammation also involves aberrant vasculature and pathologicalangiogenesis. Such disease states as ulcerative colitis and Crohn'sdisease show histological changes with the ingrowth of new blood vesselsinto the inflamed tissues. Bartonellosis, a bacterial infection found inSouth America, can result in a chronic stage that is characterized byproliferation of vascular endothelial cells.

Another pathological role associated with aberrant vasculature andangiogenesis is found in atherosclerosis. The plaques formed within thelumen of blood vessels have been shown to have angiogenic stimulatoryactivity. There is particular evidence of the pathophysiologicalsignificance of angiogenic markers, such as VEGF, in the progression ofhuman coronary atherosclerosis, as well as in recanalization processesin obstructive coronary diseases. The present invention provides aneffective treatment for such conditions.

One of the most frequent angiogenic diseases of childhood is thehemangioma. In most cases, the tumors are benign and regress withoutintervention. In more severe cases, the tumors progress to largecavernous and infiltrative forms and create clinical complications.Systemic forms of hemangiomas, the hemangiomatoses, have a highmortality rate. Therapy-resistant hemangiomas exist that cannot betreated with therapeutics currently in use, but are addressed by theinvention.

Angiogenesis is also responsible for damage found in hereditary diseasessuch as Osler-Weber-Rendu disease, or hereditary hemorrhagictelangiectasia. This is an inherited disease characterized by multiplesmall angiomas, tumors of blood or lymph vessels. The angiomas are foundin the skin and mucous membranes, often accompanied by epistaxis(nosebleeds) or gastrointestinal bleeding and sometimes with pulmonaryor hepatic arteriovenous fistula.

Angiogenesis is also involved in normal physiological processes such asreproduction and wound healing. Angiogenesis is an important step inovulation and also in implantation of the blastula after fertilization.Prevention of angiogenesis according to the present invention could beused to induce amenorrhea, to block ovulation or to prevent implantationby the blastula. In wound healing, excessive repair or fibroplasia canbe a detrimental side effect of surgical procedures and may be caused orexacerbated by angiogenesis. Adhesions are a frequent complication ofsurgery and lead to problems such as small bowel obstruction. This canalso be treated by the invention.

Each of the foregoing diseases and disorders, along with all types oftumors, are also contemplated for treatment according to the presentinvention. U.S. Pat. No. 5,712,291 is specifically incorporated hereinby reference to further demonstrate the knowledge in the art that oncethe inhibition of angiogenesis has been shown using a particular agent,the treatment of an extensive range of diseases associated with aberrantangiogenesis using that and like agents can reasonably be carried out.U.S. Pat. No. 6,524,583 is also specifically incorporated herein byreference for similar purposes and to particularly demonstrate that thisprinciple applies to the inhibition of angiogenesis and the treatment ofangiogenic diseases using antibody-based therapeutics. Theanti-angiogenic effects of the 3G4 antibody (ATCC 4545) in tumor-bearingmice (FIG. 17A) is thus important evidence that 3G4 and like antibodiesare suitable for treating a wide range of angiogenic diseases.

The invention further provides compositions and methods for use intreating other diseases in which aminophospholipids and/or anionicphospholipids, particularly PS and PE, play a role. For example, as PSis involved in cell adhesion, inflammatory responses and septic shock,antibodies to PS can be used in the treatment of inflammation and septicshock. The use of the 3G4 (ATCC 4545) or like antibodies is preferredfor such embodiments, particularly an Fab dimer of such an antibody. Aduramycin Fab dimer is also particularly contemplated for use intreating septic shock.

Aminophospholipids and/or anionic phospholipids, particularly PS, arealso involved in sickle cell anaemia, in particular, as part of theclearance mechanism. Antibodies to PS can therefore be used to treat orameliorate sickle cell anaemia. The use of the 3G4 (ATCC 4545) or likeantibodies is preferred, particularly an Fab dimer thereof.

Most bacteria express the anionic phospholipid, PA. Antibodies that bindto PA, optionally with binding to other anionic phospholipids, cantherefore be used as anti-bacterial agents. Although the antibodies ofthe invention can be prepared in E. coli, and are thus not bacteriocidalin all circumstances, an anti-bacterial role in vivo is believed toresult from the ability to fix complement. An intact antibody ratherthan an antibody fragment should therefore be used as an anti-bacterialagent. The 3G4 (ATCC 4545) and like antibodies are preferred for use insuch embodiments, although any antibody that fixes complement and bindsto PA may be employed, such as other PA-binding antibodies from Table 4.

Antiphospholipid syndrome and lupus, autoimmune disorders in whichantibodies are produced against the body's own phospholipids, areassociated with coagulation disorders, including miscarriages andthrombocytopenia (low platelet counts). Accordingly, theanti-phospholipid antibodies in these patients are pathogenicantibodies, which cause thrombosis. The antibodies of the presentinvention, however, bind to aminophospholipids and anionic phospholipidswithout exhibiting such side effects. Accordingly, the antibodies of theinvention are contemplated for use in treating antiphospholipidsyndrome, associated diseases and complications thereof.

The pathogenic anti-phospholipid antibodies that circulate in patientswith antiphospholipid syndrome are believed to bind to PS, PE and otherphospholipids in combination with proteins, such as β₂-glycoprotein I,prothrombin, kininogens, prekallikrein and factor XI (Rote, 1996; Sugiand McIntyre, 1995; 1996a; 1996b). β₂-glycoprotein I and prothrombinbound to PS are reported to be the primary antigens for anti-cardiolipinantibodies and lupus antibodies, respectively. Certain of the antibodiesof the present invention have been particularly selected on the basis ofnot binding to aminophospholipids and anionic phospholipids only in thepresence of serum proteins. Therefore, by binding to the phospholipidcomponent, certain of the antibodies of the invention are contemplatedfor use in antagonizing or competing with the pathogenic antibodies insuch patients, thus displacing the pathogenic antibodies from theirphospholipid-protein targets in the body.

Q. PE-Binding Peptide Derivatives and Conjugates

In addition to antibodies and immunoconjugates, the present inventionfurther provides PE-binding peptide derivatives and various uses,particularly in the treatment of tumors and viral diseases. Currentlypreferred PE-binding peptide constructs and derivatives are those basedupon the peptide termed duramycin. Three general categories ofPE-binding peptide and duramycin derivatives are provided by theinvention, two of which use the PE-binding peptide or duramycin as thetargeting portion of the construct, and the other uses the duramycin orlike agent mainly as the effector portion of the construct.

The use of PE-binding peptides, preferably duramycin, as targetingagents is based on their ability to impart a selective binding capacityto a resultant construct. Accordingly, a construct or conjugatecontaining a PE-binding peptide, preferably duramycin, will specificallybind to PE-expressing cells, such as tumor vascular endothelial cells,malignant tumor cells, proliferating cells and/or virally infectedcells.

As PE-binding peptides such as duramycin have biological activity inaddition to the PE targeting function, it is not necessary to conjugatea PE-binding peptide such as duramycin to a therapeutic agent to achievea therapeutic conjugate. However, as PE-binding peptides such asduramycin have associated toxicities in their natural form, the peptideshould be modified to reduce toxicity. The toxicities are connected withthe ability of the peptides to form clusters, form pores in cellmembranes, and to generally permeate or penetrate into the cells.Accordingly, these functions should be attenuated, to significantly orsubstantially prevent the PE-binding peptide from forming clusters,permeating into the cells and being non-specifically toxic. Preferably,whilst the ability to bind to PE is substantially maintained, theability of the PE-binding peptides to form clusters and penetrate cellsis substantially inhibited, thus significantly reducing or abolishingcytotoxicity.

The first category of PE-binding peptide derivatives with reducedtoxicity provided by the present invention is that in which thePE-binding peptide, preferably duramycin, is rendered relatively orsubstantially cell impermeant. This is preferably achieved by attachingto a cell impermeant group, which can be a small group with positive ornegative charge or a polar group, or can be in the form of an inertcarrier. The terms “cell impermeant group” and “cell impermeantPE-binding peptide”, as used herein, are relative rather than absolute,and refer to modified PE-binding peptides, preferably duramycin, inwhich the ability to form clusters and permeate cells has beensignificantly, and preferably substantially, reduced. The resultant cellimpermeant PE-binding peptides may function by trapping PE, andassociated membrane molecules, on the exterior of cells and/or bybringing host defenses to bear on the peptide-coated cells.

Within this category of PE-binding peptide derivatives, certainconstructs will emphasize the recruitment of host defenses, thusenhancing their therapeutic activity. For example, where a PE-bindingpeptide, preferably duramycin, is attached to an immunoglobulin, theimmunoglobulin can function both as an inert carrier and as an immuneeffector. This applies to immunoglobulins of so-called “irrelevantspecificity” and to immunoglobulin derivatives without antigen bindingcapacity, such as Fc regions. By virtue of the attached immunoglobulinor immunoglobulin derivative, such constructs will be able to redirecthost defenses against PE-expressing cells, e.g. by attracting and/oractivating immune effector cells.

In the second general category of PE-binding peptide derivatives of theinvention, the peptides are still modified to reduce cell penetrationand resultant toxicity, but rather than using a small cell impermeantgroup or inert carrier, an agent is used that changes the blood andtissue distribution of the resultant construct. Preferred examples arethose in which a PE-binding peptide, preferably duramycin, is attachedto a targeting agent that binds to a component of a tumor cell, tumor orintratumoral vasculature or tumor stroma. Although the PE-bindingpeptide itself still has a targeting property, in these aspects of theinvention, the targeting agent primarily directs the construct to thetarget tissue, such as to the tumor environment, and the attachedPE-binding peptide such as duramycin exerts a therapeutic effect upondelivery.

The third general category of PE-binding peptide derivatives returns tothe use of the PE-binding peptide, preferably duramycin, as a targetingagent to localize the derivative to PE-expressing cells. As virallyinfected cells express PE at the cell surface, as opposed to normal,uninfected cells, linking a PE-binding peptide such as duramycin to ananti-viral agent will provide an effective, targeted anti-viral agent.Although the PE-binding peptide portion, preferably duramycin, may haveadditional therapeutic effects, the attached anti-viral agent isdesigned to be the primary therapeutic agent within such constructs.

Any of the conjugation techniques described above may be used to prepareduramycin derivatives in accordance with the invention, includingcross-linkers, peptide spacers, biotin:avidin constructs and recombinantexpression. An advantageous site of attachment within the duramycinmolecule, for example, is to the lysine residue at amino acid position 2in the duramycin sequence (SEQ ID NO:9; FIG. 13P; Hayashi et al., 1990).However, linkage at this site is not a requirement of the invention.

Accordingly, PE-binding peptides, preferably duramycin, can bederivatized to have a functional group available for cross-linkingpurposes. A wide variety of groups can be used in this manner, forexample, primary or secondary amine groups, hydrazide or hydrazinegroups, carboxyl alcohol, phosphate, carbamate and alkylating groups.The agents for attachment, including anti-viral agents, may thus beconjugated through a Schiffs base linkage, a hydrazone or acyl hydrazonebond or a hydrazide linker (U.S. Pat. Nos. 5,474,765 and 5,762,918, eachspecifically incorporated herein by reference).

Q1. PE-Binding and Anti-Microbial Peptides

Any PE-binding peptide may be used in these aspects of the invention.For example, low and high molecular weight kininogens are known to bindPE. The protein and DNA sequences for a variety of such bindingproteins, including the human proteins, are known in the art,facilitating the use of PE-binding peptides therefrom. For example, thehuman genes and proteins for high and low molecular weight kininogensare described in Kitamura et al. (1985) and Kellermann et al. (1986),each specifically incorporated herein by reference.

U.S. Pat. No. 6,312,694 describes certain PE-binding conjugates usingPE-binding proteins, such as kininogens, and PE-binding fragmentsthereof. In U.S. Pat. No. 6,312,694, the PE-binding proteins orPE-binding fragments thereof are operatively attached to anti-cellularagents, toxins and coagulation factors. In the present case, PE-bindingpeptides are attached to inert carriers, tumor targeting agents oranti-viral agents. Although the present agents for attachment and theirmethods of use represent surprising advances, U.S. Pat. No. 6,312,694 isspecifically incorporated herein by reference for purposes of furtherdescribing and enabling PE-binding peptides, such as PE-binding peptidefragments of kininogens.

Currently preferred PE-binding peptides for use in the invention arethose based upon the PE-binding molecule, duramycin. Duramycin (2622U90,Molil901) is an antimicrobial peptide from the lantibiotic family (U.S.Pat. No., 4,452,782; Shotwell et al., 1958; Nakamura and Racker, 1984),and other members of the lantibiotic family may be used in the presentinvention. Where the PE-binding peptides are used as the targeting agentof the construct, for example, when linked to an inert carrier or to ananti-viral agent, a lantibiotic PE-binding peptide should substantiallyretain PE binding activity. When used as the therapeutic agent in aconstruct, particularly when attached to a tumor-targeting agent, thereis more tolerance for some loss of PE binding activity.

Testing a candidate peptide to confirm or identify those thatsubstantially bind to PE is a straightforward matter in light of thepresent disclosure and can be achieved, for example, using any one ormore of the ELISAs described herein. Lantibiotics for use as PE-bindingpeptides herein will preferably exhibit substantially the same PEbinding activity as duramycin, and even more preferably, will alsoexhibit substantially the same specificity for PE over otherphospholipids as duramycin. Such properties can also be readilydetermined in light of the present disclosure, particularly the workingexamples.

Based upon the criteria above, the following lantibiotics may be used aspart of the constructs and conjugates of the present invention:duramycin, cinnamycin, actagardine, ancovenin, epidermin, gallidermin,lanthiopeptin, mersacidin, nisin, Pep5 and subtilin. Duramycin is themost preferred PE-binding peptide for use in all aspects of theinvention. Duramycin is an antimicrobial, which has also been suggestedfor use in treating asthma, chronic bronchitis and Mycobacteriumtuberculosis infection (U.S. Pat. Nos., 5,849,706; 5,716,931; 5,683,675;5,651,957; and 5,512,269; each specifically incorporated herein byreference) and cystic fibrosis (McNulty et al., 2003). However,duramycin has not previously been described or suggested for conjugationto a cell impermeant group, particularly not for use in treating viralinfections.

Cinnamycin (Ro09-0198) is a related molecule that binds to PE (Wakamatsuet al., 1986; Choung et al., 1988a; 1988b). Labeled cinnamycin has beenused as a probe to study the transbilayer movement of PE (Aoki et al.,1994; Emoto et al., 1996) and PE exposure during apoptosis of T cells invitro (Emoto et al., 1997; Umeda and Emoto, 1999). However, therapeuticuses of cinnamycin derivatives in accordance with the present inventionhave not been previously described or suggested. Pharmaceuticalcompositions containing PE-binding peptide derivatives of the inventionbased upon cinnamycin, and various medical uses thereof, thereforerepresent an advance in the art, particularly where such compositionsare intended for use in treating viral infections.

The following anti-microbial peptides may also be used in the conjugatesof the invention, particularly as therapeutic agents attached to tumortargeting agents: cystibiotics, such as pediocin AcH/PA1, leucocin A/Ual187, mesentericin Y 105, sakacin A, sakacin P, lactacin F, cerein 7/8and carnobacteriocins, such as carnobacteriocin A, BM1 and B2; andthiolbiotics, particularly lactococcins, such as lactococcin B, A,M^(a), N^(a), G^(a) and G.

Q2. Cell Impermeant Groups

Attaching a PE-binding peptide, preferably duramycin, to a cellimpermeant group will reduce the ability of the peptides to formclusters, substantially preventing the PE-binding peptide frompermeating into normal cells and thus reducing the toxicity. The PEbinding property is maintained, however, so that the peptides canlocalize to aberrant or infected cells, which have PE exposed on thesurface.

Exemplary cell impermeant groups include groups that bear positive ornegative charge at physiological pH, such as sulfate, sulfonate,phosphate, carboxyl, phenolic, quaternary ammonium ions and aminegroups. Further examples are polar groups, such as simple sugars andpolysaccharides, amino acids and polyalcohols. Duramycin, in particular,may be linked to biotin to form biotinylated PE-binding peptides, whichcan be dispersed in a pharmaceutical composition or medicament,particularly one intended for treating a viral infection. The cellimpermeant group can also be a polypeptide, protein or immunoglobulin,any of can function as an inert carrier or as a targeting agent.

Q3. Inert Carriers

PE-binding peptides, preferably duramycin, can be rendered cellimpemeant by attachment to an inert, cell impermeant carrier. A widerange of inert, cell impermeant carriers can be conjugated to aPE-binding peptide, preferably duramycin, to prepare a cell impermeantPE-binding peptide, so long as PE binding activity is not substantiallydestroyed. The inert carriers should preferably be biologicallycompatible, such that they do not result in any significant untowardeffects upon administration to an animal or patient.

Carrier proteins can be used, and exemplary proteins are albumins andglobulins. Neutravidin and streptavidin will often be preferred.Non-protein carriers can also be used, such as natural or syntheticpolymers, including polysaccharides and PEG.

In certain embodiments, the carrier will be an immunoglobulin or portionthereof. Human immunoglobulins (HIgG) will be preferred for humanadministration. Immunoglobulins can also impart targeting functions, asdiscussed below. As an inert carrier, an immunoglobulin is one of“irrelevant specificity”, in that it does not impart a targetingfunction to the conjugate. However, certain advantages may still beachieved through the selection of particular types of immunoglobulin.For example, the Fc portion of an immunoglobulin may be used to recruithost immune cells and thus further stimulate host defenses.

Q4. Targeting Agents

Rather than attaching to an inert carrier, PE-binding peptides,preferably duramycin, can be rendered cell impermeant by attachment to atargeting agent, in particular, one that binds to a component of a tumorcell, tumor or intratumoral vasculature or tumor stroma. The targetingagent directs the construct to the target tissue, preferably the tumorenvironment, and the attached PE-binding peptide, preferably duramycin,exerts a therapeutic effect upon delivery.

Suitable targeting agents are components, such as antibodies and otheragents, which bind to a tumor cell. Agents that “bind to a tumor cell”are defined herein as targeting agents that bind to any accessiblecomponent or components of a tumor cell, or that bind to a componentthat is itself bound to, or otherwise associated with, a tumor cell, asfurther described herein.

The majority of such tumor cell-targeting agents and binding ligands arecontemplated to be agents, particularly antibodies, that bind to a cellsurface tumor antigen or marker. Many such antigens are known, as are avariety of antibodies for use in antigen binding and tumor targeting.The invention thus includes targeting agents that bind to an identifiedtumor cell surface antigen and/or that bind to an intact tumor cell. Theidentified tumor cell surface antigens and intact tumor cells of Table Iand Table II of U.S. Pat. Nos. 5,877,289; 6,004,555; 6,036,955;6,093,399 are specifically incorporated herein by reference for thepurpose of exemplifying suitable tumor cell surface antigens.

Examples of tumor cell binding regions are those that comprise anantigen binding region of an antibody that binds to the cell surfacetumor antigen p185^(HER2), milk mucin core protein, TAG-72, Lewis a orcarcinoembryonic antigen (CEA). Another group of tumor cell bindingregions are those that comprise an antigen binding region of an antibodythat binds to a tumor-associated antigen that binds to the antibody9.2.27, OV-TL3, MOv8, B3 (ATCC HB 10573), KS1/4 (obtained from a cellcomprising the vector pGKC2310 (NRRL B-18356) or the vector pG2A52 (NRRLB-18357), 260F9 (ATCC HB 8488) or D612 (ATCC HB 9796). D612 is describedin U.S. Pat. No. 5,183,756, and has ATCC Accession No. HB 9796; B3 isdescribed in U.S. Pat. No. 5,242,813, and has ATCC Accession No. HB10573; and recombinant and chimeric KS1/4 antibodies are described inU.S. Pat. No. 4,975,369; each incorporated herein by reference.

Targetable components of tumor cells further include components releasedfrom necrotic or otherwise damaged tumor cells, including cytosolicand/or nuclear tumor cell antigens. These are preferably insolubleintracellular antigen(s) present in cells that may be induced to bepermeable, or in cell ghosts of substantially all neoplastic and normalcells, that are not present or accessible on the exterior of normalliving cells of a mammal.

U.S. Pat. Nos. 5,019,368, 4,861,581 and 5,882,626, issued to AlanEpstein and colleagues, are each specifically incorporated herein byreference for purposes of even further describing and teaching how tomake and use antibodies specific for intracellular antigens that becomeaccessible from malignant cells in vivo. The antibodies described aresufficiently specific to internal cellular components of mammalianmalignant cells, but not to external cellular components. Exemplarytargets include histones, but all intracellular components specificallyreleased from necrotic tumor cells are encompassed.

Upon administration to an animal or patient with a vascularized tumor,such antibodies localize to the malignant cells by virtue of the factthat vascularized tumors naturally contain necrotic tumor cells, due tothe process(es) of tumor re-modeling that occur in vivo and cause atleast a proportion of malignant cells to become necrotic. In addition,the use of such antibodies in combination with other therapies thatenhance tumor necrosis serves to enhance the effectiveness of targetingand subsequent therapy. These types of antibodies may thus be used astargeting agents as disclosed herein.

A range of suitable targeting agents are available that bind to markerspresent on tumor endothelium and stroma, but largely absent from normalcells, endothelium and stroma. For tumor vasculature targeting, thetargeting antibody or ligand will often bind to a marker expressed by,adsorbed to, induced on or otherwise localized to the intratumoral bloodvessels of a vascularized tumor. “Components of tumor vasculature” thusinclude both tumor vasculature endothelial cell surface molecules andany components, such as growth factors, that may be bound to these cellsurface receptors or molecules. The following patents are specificallyincorporated herein by reference for the purposes of even furthersupplementing the present teachings regarding the preparation and use oftargeting agents directed against expressed, adsorbed, induced orlocalized markers of tumor vasculature: U.S. Pat. Nos. 5,855,866;5,776,427; 5,863,538; 5,660,827; 5,855,866; 5,877,289; 6,004,554;5,965,132; 6,036,955; 6,093,399; 6,004,555.

Examples of surface-expressed targets of tumor and intratumoral bloodvessels include vascular cell surface receptors and cell adhesionmolecules (Thorpe and Ran, 2000, specifically incorporated herein byreference, see Table 1). Suitable examples include endoglin, targetedby, e.g., TEC-4, TEC-11, E-9 and Snef antibodies; E-selectin, targetedby, e.g., H4/18 antibodies; VCAM-1, targeted by, e.g., E1/6 and 1.4c3antibodies; endosialin, targeted by, e.g., FB5 antibodies; α_(v)β₃integrin, targeted by, e.g., LM609 and peptide targeting agents; theVEGF receptor VEGFR1, targeted by a number of antibodies, andparticularly by VEGF; the VEGF receptor complex, also targeted by anumber of antibodies, such as 3E7 and GV39; and PSMA, targeted byantibodies such as J591. Examples such as endoglin, TGFβ receptors,E-selectin, P-selectin, VCAM-1, ICAM-1, a ligand reactive with LAM-1, aVEGF/VPF receptor, an FGF receptor, α_(v)β₃ integrin, pleiotropin,endosialin are further described and enabled in U.S. Pat. Nos.5,855,866; 5,877,289; 6,004,555; 6,093,399; each incorporated herein byreference.

Further suitable examples include proteoglycans, such as NG2, and matrixmetalloproteinases (MMPs), such as MMP2 and MMP9, each targeted byparticular peptide targeting agents (Thorpe and Ran, 2000). These areexamples of remodeling enzymes that are expressed as targetable entitiesin the tumor, which is a site of vascular remodeling. Further suitabletargets are thrombomodulin, Thy-1 and cystatin. Studies identifyingsequences elevated in tumor endothelium have also identifiedthrombomodulin, MMP 11 (stromelysin), MMP 2 (gelatinase) and variouscollagens as targetable tumor vascular markers, which is also inaccordance with U.S. Pat. Nos. 6,004,555 and 6,093,399, specificallyincorporated herein by reference.

Another suitable target is PSMA (prostate-specific membrane antigen).PSMA, initially defined by monoclonal antibody 7E11, was originallyidentified as a marker of prostate cancer and is known to be a type 2integral membrane glycoprotein. The 7E11 antibody binds to anintracellular epitope of PSMA that, in viable cells, is not availablefor binding. In the context of the present invention, PSMA is thustargeted using antibodies to the extracellular domain. Such antibodiesreact with tumor vascular endothelium in a variety of carcinomas,including lung, colon and breast, but not with normal vascularendotheliun.

Many antibodies that bind to the external domain of PSMA are readilyavailable and may be used in the present invention. Monoclonalantibodies 3E11, 3C2, 4E10-1.14, 3C9 and 1G3 display specificities fordiffering regions of the extracellular domain of the PSMA protein andare suitable for use herein. Three additional antibodies to theextracellular domain of PSMA are J591, J415 and PEQ226.5, which confirmPSMA expression in tumor-associated vasculature and may be used in theinvention. As the nucleic acids encoding PSMA and variants thereof arealso readily available, U.S. Pat. Nos. 5,935,818 and 5,538,866,additional antibodies can be generated if desired.

U.S. Pat. No. 6,150,508, specifically incorporated herein by reference,describes various other monoclonal antibodies that bind to theextracellular domain of PSMA, which may be used in the presentinvention. Any one or more of the thirty-five exemplary monoclonalantibodies reactive with PSMA expressed on the cell surface may be used.These include, 3F5.4G6 (ATCC HB12060); 3D7-1.I. (ATCC HB12309);4E10-1.14 (ATCC HB12310); 3E11 (ATCC HB12488); 4D8 (ATCC HB12487); 3E6(ATCC HB12486); 3C9 (ATCC HB12484); 2C7 (ATCC HB12490); 1G3 (ATCCHB12489); 3C4 (ATCC HB12494); 3C6 (ATCC HB12491); 4D4 (ATCC HB12493);1G9 (ATCC HB12495); 5C8B9 (ATCC HB12492); 3G6 (ATCC HB12485); and 4C8B9(ATCC HB12492).

Further antibodies, or binding portions thereof, that recognize anextracellular domain of PSMA are described in U.S. Pat. Nos. 6,107,090and 6,136,311, each specifically incorporated herein by reference. Fourhybridoma cell lines in particular are described, being E99, J415, J533,and J591 (ATCC HB-12101, HB-12109, HB-12127, and HB-12126), any one ormore of which may thus be used as a targeting agent in accordance withthe claimed invention.

Targeting agents that bind to “adsorbed” targets are another suitablegroup, such as those that bind to ligands or growth factors that bind totumor or intratumoral vasculature cell surface receptors. Suchantibodies include those that bind to VEGF, FGF, TGFβ, HGF, PF4, PDGF,TIMP or a tumor-associated fibronectin isoform (U.S. Pat. Nos.5,877,289; 5,965,132; 6,093,399 and 6,004,555; each incorporated hereinby reference).

Other suitable targeting antibodies, or fragments thereof, are thosethat bind to epitopes that are present on ligand-receptor complexes orgrowth factor-receptor complexes, but absent from both the individualligand or growth factor and the receptor. Such antibodies will recognizeand bind to a ligand-receptor or growth factor-receptor complex, aspresented at the cell surface, but will not bind to the free ligand orgrowth factor or the uncomplexed receptor. A “bound receptor complex”,as used herein, therefore refers to the resultant complex produced whena ligand or growth factor specifically binds to its receptor, such as agrowth factor receptor.

These aspects are exemplified by the VEGF/VEGF receptor complex. Suchligand-receptor complexes will be present in a significantly highernumber on tumor-associated endothelial cells than on non-tumorassociated endothelial cells, and may thus be targeted by anti-complexantibodies. Anti-complex antibodies include the monoclonal antibodies2E5, 3E5 and 4E5 and fragments thereof.

Antigens naturally and artificially inducible by cytokines andcoagulants may also be targeted. Exemplary cytokine-inducible antigensare E-selectin, VCAM-1, ICAM-1, endoglin, a ligand reactive with LAM-1,and even MHC Class II antigens, which are induced by, e.g., IL-1, IL-4,TNF-α, TNF-β or IFN-γ, as may be released by monocytes, macrophages,mast cells, helper T cells, CD8-positive T-cells, NK cells or even tumorcells.

Further inducible antigens include those inducible by a coagulant, suchas by thrombin, Factor IX/IXa, Factor X/Xa, plasmin or ametalloproteinase (matrix metalloproteinase, MMP). Generally, antigensinducible by thrombin will be used. This group of antigens includesP-selectin, E-selectin, PDGF and ICAM-1, with the induction andtargeting of P-selectin and/or E-selectin being generally preferred.

In other embodiments, the vasculature and stroma targeting agents (seebelow) of the invention will be targeting agents that are themselvesbiological ligands, or portions thereof, rather than an antibodies.“Biological ligands” in this sense will be those molecules that bind toor associate with cell surface molecules, such as receptors, that areaccessible in the stroma or on vascular cells; as exemplified bycytokines, hormones, growth factors, and the like. Any such growthfactor or ligand may be used so long as it binds to thedisease-associated stroma or vasculature, e.g., to a specific biologicalreceptor present on the surface of a tumor vasculature endothelial cell.

Suitable growth factors for use in these aspects of the inventioninclude, for example, VEGF/VPF (vascular endothelial growthfactor/vascular permeability factor), FGF (the fibroblast growth factorfamily of proteins), TGFβ (transforming growth factor B), atumor-associated fibronectin isoform, scatter factor/hepatocyte growthfactor (HGF), platelet factor 4 (PF4), PDGF (platelet derived growthfactor), TIMP or even IL-8, IL-6 or Factor XIIIa. VEGF/VPF and FGF willoften be preferred.

Further suitable targeting agents are those that bind totumor-associated stroma. During tumor progression, the extracellularmatrix of the surrounding tissue is remodeled through two mainprocesses: the proteolytic degradation of extracellular matrixcomponents of normal tissue; and the de novo synthesis of extracellularmatrix components by tumor cells and stromal cells activated bytumor-induced cytokines. These two processes generate a “tumorextracellular matrix” or “tumor stroma”, which is permissive for tumorprogression and is qualitatively and quantitatively distinct from theextracellular matrices or stroma of normal tissues.

The “tumor stroma” thus has targetable components that are not presentin formal tissues. Certain preferred tumor stromal targeting agents foruse in the invention are those that bind to basement membrane markers,type IV collagen, laminin, heparan sulfate, proteoglycan, fibronectins,activated platelets, LIBS, RIBS and tenascin. The following patents arespecifically incorporated herein by reference for the purposes of evenfurther supplementing the present teachings regarding the preparationand use of tumor stromal targeting agents: U.S. Pat. Nos. 5,877,289;6,093,399; 6,004,555; and 6,036,955.

Components of tumor-associated stroma include structural and functionalcomponents of the stroma, extracellular matrix and connective tissues.Tumor stroma targeting agents thus include those that bind to componentssuch as basement membrane markers, type IV collagens, laminin, fibrin,heparan sulfate, proteoglycans, glycoproteins, anionic polysaccharidessuch as heparin and heparin-like compounds and fibronectins.

Exemplary useful antibodies are those that bind to tenascin, a largemolecular weight extracellular glycoprotein expressed in the stroma ofvarious benign and malignant tumors. Anti-tenascin antibodies may thusbe used as targeting agents (U.S. Pat. Nos. 6,093,399 and 6,004,555,specifically incorporated herein by reference).

Further suitable targeting agents include antibodies and ligands thatbind to a smooth muscle cell, a pericyte, a fibroblast, a macrophage,and an infiltrating lymphocyte or leucocyte. “Activated platelets” arefurther components of tumor stroma, as platelets bind to the stroma whenactivated, and such platelets may thus be targeted by the invention.

Further suitable stromal targeting agents, antibodies and antigenbinding regions thereof bind to “inducible” tumor stroma components,such as those inducible by cytokines, and especially those inducible bycoagulants, such as thrombin. A group of preferred anti-stromalantibodies are those that bind to RIBS, the receptor-induced bindingsite, on fibrinogen. “RIBS” is thus a targetable antigen, the expressionof which in stroma is dictated by activated platelets. Antibodies thatbind to LIBS, the ligand-induced binding site, on activated plateletsare also useful.

Particularly preferred targetable elements of tumor-associated stromaare currently the tumor-associated fibronectin (FN) isoforms.Fibronectins are multifunctional, high molecular weight glycoproteinconstituents of both extracellular matrices and body fluids. They areinvolved in many different biological processes, such as theestablishment and maintenance of normal cell morphology, cell migration,haemostasis and thrombosis, wound healing and oncogenic transformation.

Fibronectin isoforms are ligands that bind to the integrin family ofreceptors. “Tumor-associated fibronectin isoforms” may be considered tobe part of the tumor vasculature and/or the tumor stroma. Fibronectinisoforms have extensive structural heterogeneity, which is brought aboutat the transcriptional, post-transcriptional and post-translationallevels.

Structural diversity in fibronectins is first brought about byalternative splicing of three regions (ED-A, Ed-B and IIICS) of theprimary fibronectin transcript to generate at least 20 differentisoforms. As well as being regulated in a tissue- anddevelopmentally-specific manner, it is known that the splicing patternof fibronectin-pre-mRNA is deregulated in transformed cells and inmalignancies. In fact, the fibronectin isoforms containing the ED-A,ED-B and IIICS sequences are expressed to a greater extent intransformed and malignant tumor cells than in normal cells.

In particular, the fibronectin isoform containing the ED-B sequence (B+isoform), is highly expressed in foetal and tumor tissues as well asduring wound healing, but restricted in expression in normal adulttissues. B+ fibronectin molecules are undetectable in mature vessels,but upregulated in angiogenic blood vessels in normal situations (e.g.,development of the endometrium), pathological angiogenesis (e.g., indiabetic retinopathy) and in tumor development. The so-called B+ isoformof fibronectin (B-FN) is thus particularly suitable for use with thepresent invention.

The ED-B sequence is a complete type III-homology repeat encoded by asingle exon and comprising 91 amino acids. The presence of B+ isoformitself constitutes a tumor-induced neoantigen, but in addition,ED-expression exposes a normally cryptic antigen within the type IIIrepeat 7 (preceding ED-B); since this epitope is not exposed infibronectin molecules lacking ED-B, it follows that ED-B expressioninduces the expression of neoantigens both directly and indirectly. Thiscryptic antigenic site forms the target of the monoclonal antibody, BC-1(European Collection of Animal Cell Cultures, Porton Down, Salisbury,UK, number 88042101). The BC1 antibody may be used as a vasculartargeting component of the present invention.

Improved antibodies with specificity for the ED-B isoform are describedin WO 97/45544, specifically incorporated herein by reference. Suchantibodies have been obtained as single chain Fvs (scFvs) from librariesof human antibody variable regions displayed on the surface offilamentous bacteriophage (see also WO 92/01047, WO 92/20791, WO93/06213, WO 93/11236 and WO 93/19172).

Using an antibody phage library, specific scFvs can be isolated both bydirect selection on recombinant fibronectin-fragments containing theED-B domain and on recombinant ED-B itself when these antigens arecoated onto a solid surface (“panning”). These same sources of antigenhave also been successfully used to produce “second generation” scFvswith improved properties relative to the parent clones in a process of“affinity maturation”. The isolated scFvs react strongly andspecifically with the B+ isoform of human fibronectin, preferablywithout prior treatment with N-glycanase.

The antibodies of WO 97/45544 are thus particularly contemplated for useherewith. In anti-tumor applications, these human antibodyantigen-binding domains are advantageous as they have less side-effectsupon human administration. The referenced antibodies bind the ED-Bdomain directly. Preferably, the antibodies bind both human fibronectinED-B and a non-human fibronectin ED-B, such as that of a mouse, allowingfor testing and analysis in animal models. The antibody fragments extendto single chain Fv (scFv), Fab, Fab′, F(ab′)₂, Fabc, Facb and diabodies.

Even further improved antibodies specific for the ED-domain offibronectin have been produced with sub-nanomolar dissociationconstants, as described in WO 99/58570, and are thus even more preferredfor use herewith. These targeting agents are exemplified by the L19antibody, described in WO 99/58570, specifically incorporated herein byreference for the purpose of teaching how to make and use this andrelated antibodies. These antibodies have specific affinity for acharacteristic epitope of the ED-B domain of fibronectin and haveimproved affinity to the ED-B epitope.

Such improved recombinant antibodies are available in scFv format, froman antibody phage display library. In addition to H10 and L19, thelatter of which has a dissociation constant for the ED-B domain offibronectin in the sub-nanomolar concentration range, the techniques ofWO 99/58570, specifically incorporated herein by reference, may be usedto prepare like antibodies. The isolation of human scFv antibodyfragments specific for the ED-B domain of fibronectin from antibodyphase-display libraries and the isolation of a human scFv antibodyfragment binding to the ED-B with sub-nanomolar affinity areparticularly described in Examples 1 and 2 of WO 99/58570.

Preferred antibodies thus include those with specific affinity for acharacteristic epitope of the ED-B domain of fibronectin, wherein theantibody has improved affinity for the ED-B epitope, wherein theaffinity is in the subnanomolar range, and wherein the antibodyrecognizes ED-B(+) fibronectin. Other preferred formats are wherein theantibody is a scFv or recombinant antibody and wherein the affinity isimproved by introduction of a limited number of mutations in its CDRresidues. Exemplary residues to be mutated include 31-33, 50, 52 and 54of the VH domain and residues 32 and 50 of its VL domain. Suchantibodies are able to bind the ED-B domain of fibronectin with a Kd of27 to 54 pM; as exemplifed by the L19 antibody or functionallyequivalent variants form of L19.

Q5. Anti-Viral Conjugates

Under normal conditions, PE is not exposed at the cell surface. However,in various disease states, PE becomes exposed at the cell surface of oneor more cell types. For example, endothelial cells within tumorvasculature become PE-positive and can be targeted by PE-directedtherapeutics, as shown herein by the successful tumor treatment usingduramycin conjugated to HuIgG. PE also becomes exposed at the cellsurface of virally infected cells, which are thus additional targets fortherapeutic intervention using the PE-binding peptide derivatives of thepresent invention. Indeed, the present application shows that duramycinderivatives, as exemplified by those linked to biotin and HuIgG, areeffective anti-viral agents, both in vitro and in vivo.

Several anti-viral drugs, including AZT, acyclovir, gancyclovir,cidofovir (cytosine derivative) and new anti-viral drugs are limited bytoxicity/efficacy. Based on their observations regarding changes in PEduring viral infection, and further in light of the effectiveness of theoriginal PE-binding peptide derivatives, the present inventors haveaddressed problems in the anti-viral field by designing new anti-viraltherapeutics with reduced toxicity and increased efficacy. In the newanti-viral therapeutics of the invention, anti-viral drugs are linked toPE-binding peptides, which function to deliver the attached anti-viraldrugs to virally infected cells.

In addition, the inventors have the following observations in regard tothe development of the PE-binding peptide, anti-viral derivatives of thepresent invention. Data are presented herein to show that PE-bindingpeptide derivatives, e.g., duramycin-L-biotin, are taken up bymacrophages in vivo, especially in the lung, even after systemicadministration. On infection, many viruses first pass through cells ofthe reticuloendothelial cell system (RES), and the macrophage is themain cell for viral uptake. Therefore, by linking anti-viral drugs toPE-binding peptides such as duramycin, the anti-viral effect of the drugis directed to the primary cell type (macrophage) responsible forclearing invading viruses.

As the PE-binding peptide derivatives localize to macrophages in thelung after systemic administration will naturally be effective.Administration to the lung by more direct means, including via aerosol,is also envisioned. The present invention therefore solves importantdeficiencies in the viral treatment field by providing widely applicableand practical anti-viral remedies.

The new anti-viral therapeutics of the present invention thus comprise aPE-binding peptide, such as duramycin, linked to an anti-viral drug,preferably using a biologically releasable or hydrolytically labile bondto link the two agents. Any of a range of anti-viral agents, includingany agent developed as an anti-viral in the future, may be linked to aPE-binding peptide to form an advantageous anti-viral therapeutic inaccordance with this invention. In addition to so-called classicanti-viral agents, other DNA/RNA inhibitors may also be attached to aPE-binding peptide to form an anti-viral therapeutic. Exemplaryanti-viral agents are listed in Table G, any one or more of which may beattached to a PE-binding peptide to prepare an anti-viral conjugate ofthe invention, or can be used separately in the anti-viral combinationtherapies of the invention.

TABLE G Common Disease-Causing Viruses and Anti-Viral DrugsDisease-Causing Exemplary Viruses Drug Categories Anti-Viral DrugsHerpes virus Cidofovir, acyclovir, penciclovir (famciclovir),gancyclovir (ganciclovir), deoxyguanosine, foscarnet, idoxuridine,trifluorothymidine, vidarabine, sorivudine Retroviruses Nucleosidereverse Zidovudine, didanosine, transcriptase (RT) zalcitabine,lamivudine, inhibitors stavudine, abacavir, multinucleoside resistanceA, multinucleoside resistance B Non-nucleoside RT Nevirapine,delavirdine, inhibitors efavirenz, Adefovir Dipivoxil ProteaseInhibitors Indinavir, ritonavir, saquinavir, nelfinavir, amprenavir Cellcycle phase Hydroxyurea (Hydrea ™, specific Bristol Myers-Squibb)antineoplastic Hepatitis B Deoxycytosine iphosphate, lamivudinetriphosphate, emticitabine triphosphate, adefovir diphosphate,penciclovir triphosphate, lobucavir triphosphate Hepatitis C Interferonalpha, ribavirin Influenza Amantadine, rimantadine, A and B zanamivir,oseltamivir

Within the range of anti-viral agents and drugs, AZT and cidofovir arecurrently preferred for linking to a PE-binding peptide. Irrespective ofthe chosen anti-viral drug, the PE-binding peptide, anti-viral conjugatewill bind to macrophages in the lungs, to virally infected cells and mayalso bind to virus particles. Depending on the linker or conjugationtechnology used, the anti-viral drug may be released at the surface ofthe target cell and then be taken up into the cell. Preferably, theconjugate itself is taken up into the cell, such as a macrophage orvirally infected cell. Uptake can either occur naturally or can bevirus-mediated. Once inside the cell, as with an antibody conjugate,hydrolysis of the linker releases the active anti-viral agent.

One example of a suitable linkage option for a duramycin-cidofoviranti-viral agent is set forth in FIG. 13R. In this example, theduramycin-cidofovir conjugate is designed to bind to macrophages in thelungs and be taken into the cell. Hydrolysis of the linker leads todecomposition of phosphoramidate and release of active cidofovir or acell permeable derivative (R in FIG. 13R) that breaks down to cidofovir.

Other linkages containing biologically labile bonds can be used, suchas, e.g., disulfide, acid labile, enzymatically cleavable orhydrolysable. Accordingly, any biologically-releasable or selectivelyhydrolyzable bond described for use in linking antibodies to therapeuticagents can be used in connection with the PE-binding peptide, anti-viralderivatives of the present invention. The choice of linker is notlimited by the particular PE-binding peptide, such as duramycin, as thepeptide can be derivatized to introduce functional groups permitting theattachment of the selected anti-viral agent, as described above.

R. Anti-Viral Treatment Methods

The present invention further provides a range of antibodies,immunoconjugates and PE-binding peptide derivatives, optionallyconjugated to anti-viral agents, for use in treating viral infections.The treatment regimens, and particularly the doses, are generally asdescribed above for the cancer treatment aspects of the presentinvention, which adaptability is an advantage of the invention overall.Although an understanding of the particular mechanism(s) of action isnot necessary to practice the anti-viral treatment of the invention,certain of the reasons underlying the viral treatment, as supported bythe working examples herein, are as follows.

The most important mechanisms are believed to be connected with viralreplication and activation of the host cell. During viral infection, thevirus activates the cell during its replication process inside the cell.This process of cell activation is necessary for viral replication, asshown for herpes viruses, hepatitis C and HIV-1. Viral progressionactivates gene expression, both viral and host. For example, thereplication of Pichinde virus and Machupo virus is inhibited byactinomycin D late in the replication cycle, indicating that host cellgene transcription is needed for completion of viral replication.

The activation of the host cell by the virus causes the cell toexternalize anionic phospholipids and aminophospholipids, such PS andPE. In particular, the inventors reason that viral activation causesCa²⁺ fluxes into the cell, which activate scramblase, externalizinganionic phospholipids and aminophospholipids, particularly PS and PE.Antibodies, peptide derivatives and conjugates that bind anionicphospholipids and aminophospholipids, preferably PS and PE, then bindand interfere with the activation process, preventing the virus frombeing able to replicate properly.

The present examples show that the invention acts late in the process ofviral infection, blocking viral maturation or egress. The inventors'studies show that the inhibitory effect of the agents of the inventionis widely applicable, as it has been shown to operate on viruses thatuse different egression mechanisms. For example, the present examplesdemonstrate block of herpes virus (CMV), which escapes fromGolgi-derived exocytotic vesicles, and block of arenavirus (Pichindevirus) and paramyxovirus (RSV), which bud out directly from the plasmamembrane.

Virally infected cells externalize anionic phospholipids andaminophospholipids, particularly PS and PE, which are normallyintracellular, i.e., confined to the inner surface of plasma membrane.During escape of the virus, phospholipids redistribute at the site ofescape, accommodating membrane bending during viral budding orexocytosis from the plasma membrane, and anionic phospholipids andaminophospholipids are externalized during this process. The antibodies,peptide derivatives and conjugates of the invention can thus bind to theexternalized anionic phospholipids and aminophospholipids, particularlyPS and PE, and block the escape of the virus from the infected cell.Binding of the constructs of the invention to virally infected cells isalso shown in the present examples.

The antibodies, peptide derivatives and conjugates of the invention mayfurther bind to the externalized anionic phospholipids andaminophospholipids, particularly PS and PE, and interfere with one ormore signaling pathways necessary for viral gene expression and/orreplication.

Moreover, enveloped virions themselves likely have anionic phospholipidsand aminophospholipids, such as PS and PE, on their external surface.Since viruses lack a translocase to maintain or restore phospholipidasymmetry, continued exposure of phospholipids such as PS and PE isexpected. The antibodies, peptide derivatives and conjugates of theinvention may thus cause opsonization, complement binding, phagocytosisby host cells such as macrophages and clearance of free virus particles.

In a further aspect of the invention, viruses likely need anionicphospholipids and aminophospholipids for infection and/or syncitiaformation. The antibodies, peptide derivatives and conjugates of theinvention may further block these aspects of the viral life cycle bybinding to anionic phospholipids and aminophospholipids.

According to the foregoing insights, and in light of the presentexamples, the spectrum of viral treatment for the present inventionextends to any virus, whether enveloped or not, DNA or RNA. As theanionic phospholipid- and aminophospholipid-binding antibodies, peptidederivatives and conjugates of the invention at least in part block viralreplication inside the cell, and/or prevent escape of virus from cells,the invention is not limited to the treatment of enveloped virusesalone, nor to any particular virus, which is an important advantage. Forexample, work published subsequent to the invention reports that annexinV and PS vesicles can inhibit HIV-1 infection of macrophages, but cannotinhibit HIV-1 infection of T cells or inhibit other viruses, such asvesicular stomatitis virus G and amphotropic murine leukemia virus(Callahan et al., 2003).

Naturally, the antibodies, peptide derivatives and conjugates of theinvention do act on enveloped viruses, particularly those viruses thathave anionic phospholipids and aminophospholipids, of PS and PE, on theouter surface of the envelope, wherein the antibodies, peptidederivatives and conjugates cause viral clearance and/or inhibiting viralentry of target cells.

An important aspect of the present invention is therefore that it isuniversally applicable, being suitable for the treatment of recombinant,engineered and synthetic viruses, e.g., created as part ofbio-terrorism. Indeed, the invention is not limited to the treatment ofanimals and humans. As the categories of hosts found in the virus taxainclude algae, archaea, bacteria, fungi, invertebrates, mycoplasma,plants, protozoa, spiroplasma and vertebrates, the invention can be usedto inhibit viral infection and replication in any such setting,including in viruses of agricultural importance. The treatment of viralinfection and associated diseases in vertebrates is currently preferred,and any one or more of the viruses in Table H, which infect vertebrateanimals, may be inhibited, and the resultant infection treated, usingthe present invention.

TABLE H Viruses of Vertebrates Family Genus Type Species AdenoviridaeMastadenovirus Human adenovirus 2 Aviadenovirus Fowl adenovirus 1African Swine African swine fever Fever-like Viruses virus ArenaviridaeArenavirus Lymphocytic choriomeningitis virus Arterivirus Equinearteritis virus Astroviridae Astrovirus Human astrovirus 1 BirnaviridaeAquabirnavirus Infectious pancreatic necrosis virus AvibirnavirusInfectious bursal disease virus Bunyaviridae Bunyavirus Bunyamwera virusHantavirus Hantaan virus Nairovirus Nabrobi sheep disease virusPhlebovirus Sandfly fever Sicilian virus Caliciviridae CalicivirusVesicular exanthema of swine virus Circoviridae Circovirus Chickenanemia virus Coronaviridae Coronavirus Avian infectious bronchitis virusTorovirus Berne virus Deltavirus Hepatitis delta virus FiloviridaeFilovirus Marburg virus Flaviviridae Flavivirus Yellow fever virusPestivirus Bovine diarrhea virus Hepatitis C - Hepatitis C virus likeviruses Hepadnaviridae Orthophepadnavirus Hepatitis B virusAvihepadnavirus Duck hepatitis B virus Herpesviridae SubfamilyAlphaherpes- Simplexvirus Human herpesvirus 1 virinae VaricellovirusHuman herpesvirus 3 Subfamily: Betaherpes- Cytomegalovirus Humanherpesvirus 5 virinae Muromegalovirus Mouse cytomegalo- virus 1Subfamily Gammaherpes- Roseolovirus Human herpesvirus 6 virinaeLymphocryptovirus Human herpesvirus 4 Rhadinovirus Ateline herpesvirus 2Iridoviridae Ranavirus Frog virus 3 Lymphocystivirus Flounder virusGoldfish virus - Goldfish virus 1 like viruses OrthomyxoviridaeInfluenzavirus A, B Influenza A virus Influenzavirus C Influenza C virusThogoto-Like viruses Thogoto virus Papovaviridae Polyomavirus Murinepolyomavirus Papillomavirus Cottontail rabbit papillomavirus (Shope)Paramyxoviridae Subfamily Paramyxovirinae Parayxovirus Humanparainfluenza virus 1 Morbillivirus Measles virus Rubulavirus Mumpsvirus Subfamily Pneumovirinae Pneumovirus Human respiratory syncytialvirus Parvoviridae Subfamily Parovirinae Parvovirus Mice minute virusErythovirus B19 virus Dependovirus Adeno-associated virus 2Picornaviridae Enterovirus Poliovirus 1 Rhinovirus Human rhinovirus 1AHepatovirus Hepatitis A virus Cardiovirus Encephalomyocarditis virusAphthovirus Foot-and-mouth disease virus O Poxviridae SubfamilyChordopoxvirinae Orthopoxvirus Vaccinia virus Parapoxyvirus Orf virusAvipoxvirus Fowlpox virus Capripoxvirus Sheeppox virus LeporipoxvirusMyxoma virus Suipoxvirus Swinepox virus Molluscipoxvirus Molluscumcontagiosum virus Yatapoxvirus Yaba monkey tumor virus ReoviridaeOrthoreovirus Reovirus 3 Orbivirus Bluetonguevirus 1 Rotavirus Simianrota virus SA11 Coltivirus Colorado tick fever virus Aquareovirus Goldenshiner virus Retroviridae Mammalian type Mouse mammary B retrovirusestumor virus Mammalian type Murine leukemia C retroviruses virus Aviantype C Avian leukosis retroviruses virus Type D retrovirusesMason-Pfizer monkey virus Blv-htlv Bovine leukemia retroviruses virusLentivirus Human immuno- deficiency virus 1 Spumavirus Human spumavirusRhabdoviridae Vesiculovirus Vesicular stomatitis Indiana virusLyssavirus Rabies virus Ephemerovirus Bovine ephemeral fever TogaviridaeAlphavirus Sindbis virus Rubivirus Rubella virus

The use of the invention in treating viral infections and associateddiseases in mammals is preferred, particularly in terms of valuable orvalued animals, such as racehorses and domestic pets, and animals andbirds used to directly produce (e.g., meat) or indirectly produce (e.g.milk and eggs) food for human consumption. In addition to humantreatment exemplary embodiments of the invention include the treatmentof horses, dogs, cats and the like: the treatment of cows, pigs, boar,sheep, goat, buffalo, bison, llama, deer, elk, and other large animals,as well as their young, including calves and lambs.

The treatment of humans is particularly preferred, whether for naturallyoccurring viruses or for those created by bioterrorism. In terms ofnaturally occurring viruses and the resultant diseases, the invention isagain unlimited in its applications. Accordingly, any one or more of theviruses in Table J may be inhibited using the present invention, and theresultant infections and diseases thus treated.

TABLE J Viral Diseases in Humans Disease Virus Type of Virus AIDS HumanImmunodefi- Retrovirus ciency Virus (HIV) Bronchiolitis and viralRespiratory syncytial Paramyxovirus pneumonia virus BronchiolitisParainfluenza virus Paramyxovirus Cervical cancer Human papillomaPapovavirus virus Chicken pox Varicella Zoster Herpesvirus virus DengueDengue virus Flavivirus Ebola hemorrhagic fever Ebola virus FilovirusGenital Herpes Herpes Simplex Herpesvirus virus-2 Hantavirus hemorrhagicHantavirus Bunyavirus fever Hepatitis Hepatitis A Picornavirus HepatitisB Hepadavirus Hepatitis C Flavivirus Hepatitis D Deltavirus Hepatitis ECalcivirus Influenza Influenza viruses Orthomyxo- A, B and C virus JuninArgentinian Junin virus Arenavirus Hemorrhagic Fever Lassa hemorrhagicfever Lassa virus Arenavirus Machupo hemorrhagic Machupo virusArenavirus fever Measles Rubeola virus Paramyxovirus MononucleosisEpstein Barr virus Herpesvirus CMV disease (viral CytomegalovirusHerpesvirus pneumonia, mononucle- osis like syndrome) Severe AcuteRespiratory Human coronavirus Coronavirus Syndrome (SARS) ShinglesVaricella zoster virus Herpesvirus Smallpox Variola virus PoxvirusYellow fever Yellow fever virus Flavivirus West Nile Disease West Nilevirus Western equine Western EE virus Togavirus encephalitis Pneumonia,Hepatitis, Adenovirus Adenovirus acute respiratory diseaseGastroenteritis Rotavirus Rotavirus Encephalitis Semliki Forest virusAlphavirus Cowpox Vaccinia virus Poxvirus Encephalitis Venezuelan EEAlphavirus Meningitis, encephalitis, Lymphocytic chorio- Arenavirusmeningoencephalitis meningitis Venezuelan hemorrhagic Guanarito virusArenavirus fever Rift valley fever (hemorr- Rift valley fever virusBunyavirus hagic fever, encephalitis) Marburg Hemorrhagic Marburg virusFilovirus fever Tick borne encephalitis Tick borne encephalitisFlavivirus virus (TBEV) Encephalitis Hendra virus ParamyxovirusEncephalitis Nipah virus Paramyxovirus Crimean-Congo hemorr-Crimean-Congo Bunyavirus hagic fever hemorrhagic fever virus Brazilianhemorrhagic Sabia virus Arenavirus fever

The invention is particularly contemplated for use in the treatment ofCMV related diseases such as viral pneumonia, mononucleosis likesyndrome, and associated congenital malformations (deafness and mentalretardation); respiratory diseases, such as those caused by RSV,including bronchiolitis and viral pneumonia, influenza, the common coldand SARS; AIDS; hepatitis: cancers associated with viral infections;mononucleosis; and smallpox.

In other embodiments, the inventors particularly contemplate theinhibition of arenaviruses, which are pathogenic in man. Thearenaviruses include the Old World viruses 10 responsible for Lassafever (Lassa virus) and lymphocytic choriomeningitis (LCMV). Lassa feveris endemic in West Africa, affecting up to 300,000 people annually andcausing up to 3000 deaths. Infection with Lassa fever leads to fever andmalaise within about 10 days. Abdominal pain, nausea, vomiting anddiarrhea are common. Pharyngitis and cough may develop. Neurologicalsymptoms are usually mild. Vascular leak syndromes, such as edema andpleural effusions, are present in more severe cases. Bleeding is seenabout one quarter of patients. The disease can cause changes in thecardiovascular system that culminate in shock and death.

Arenaviruses also include and the antigenically-distinct New Worldviruses responsible for Argentine hemorrhagic fever (Junin virus),Bolivian hemorrhagic fever (Machupo virus) and Venezuelan hemorrhagicfever (Guanarito virus). All of these viruses are on the CDC Category Alist of potential bioterrorism weapons.

Although not connected with aminophospholipids or anionic phospholipids,other antibodies that bind to viruses directly have been developed intoapproved drugs. This is true of CytoGam, which is used for suppressingCMV infections in immunosuppressed patients, and Synagis, which is usedto protect newborn infants from respiratory syncitial virus. Thus, thereare no problems in the use of monoclonal antibodies to access andneutralize viruses in tissues.

The doses that are suitable for the anti-tumor embodiments are alsosuitable for the anti-viral treatments. Similarly, multipleadministration may be used for chronic infections, and high doses may beused for acute infections. Any suitable route of administration may beemployed, again as disclosed for the cancer treatment aspects, includingIV, IM, SC, as an aerosol to lungs or airways and such like.

The therapeutics provided by the invention are valuable agents havingbroad-spectrum anti-viral activity. In addition to being effectiveagainst a large number of potentially lethal viruses, the agents canalso be administered after exposure to the virus, even in settings wherethe exact nature of the virus is not known. Thus, the anti-viraltherapeutics of the present invention do not require a prolonged periodof time between identification of the pathogen and delivery of thetherapy, in marked contrast with the time and expense entailed by thedevelopment, production or delivery of specific vaccines.

The following examples are included to demonstrate preferred embodimentsof the invention. It should be appreciated by those of skill in the artthat the techniques disclosed in the examples which follow representtechniques discovered by the inventor to function well in the practiceof the invention, and thus can be considered to constitute preferredmodes for its practice. However, those of skill in the art should, inlight of the present disclosure, appreciate that many changes can bemade in the specific embodiments which are disclosed and still obtain alike or similar result without departing from the spirit and scope ofthe invention.

Example I Tumor Treatment with Anti-VCAM-1-tTF Coaguligand

The present example shows the specific coagulation of tumor vasculaturein vivo that results following the administration of a tumorvasculature-targeted coagulant (“coaguligand”) to tumor-bearing animalsand the resultant anti-tumor effects. In this coaguligand, an antibodydirected to VCAM-1 (vascular endothelial adhesion molecule-1, VCAM-1) isused as a targeting agent to deliver truncated Tissue Factor (tTF), amodified form of a human coagulant, to tumor vasculature.

The MK2.7 hybridoma, secreting a rat IgG₁ antibody against murine VCAM-1was obtained from the American Type Culture Collection (ATCC, Rockville,Md.; ATCC CRL 1909). The R187 hybridoma, secreting a rat IgG₁ antibodyagainst murine viral protein p30 gag, was also obtained from the ATCC,and was used as an isotype matched control for the anti-VCAM-1 antibody.

The blood vessels of the major organs and a tumor from mice bearingsubcutaneous L540 human Hodgkin's tumors were examinedimmunohistochemically for VCAM-1 expression using an anti-VCAM-1antibody. Overall, VCAM-1 expression was observed on 20-30% of totaltumor blood vessels stained by the anti-endoglin antibody, MJ 7/18, usedas a positive control. Constitutive vascular expression of VCAM-1 wasfound in heart and lungs in both tumor-bearing and normal animals.Strong stromal staining was observed in testis where VCAM-1 expressionwas strictly extravascular.

Mice bearing subcutaneous L540 tumors were injected intravenously withanti-VCAM-1 antibody and, two hours later, the mice were exsanguinated.The tumor and normal organs were removed and frozen sections wereprepared and examined immunohistochemically to determine the location ofthe antibody. Anti-VCAM-1 antibody was detected on endothelium of tumor,heart and lung. Staining was specific as no staining of endothelium wasobserved in the tumor and organs of mice injected with a species isotypematched antibody of irrelevant specificity, R187. No localization ofanti-VCAM-1 antibody was found in testis or any normal organ exceptheart and lung.

An anti-VCAM-1·tTF conjugate or “coaguligand” was prepared usingtruncated tissue factor (tTF). Intravenous administration of theanti-VCAM-1·tTF coaguligand induces selective thrombosis of tumor bloodvessels, as opposed to vessels in normal tissues, in tumor-bearing mice.

The anti-VCAM-1·tTF coaguligand was administered to mice bearingsubcutaneous L540 tumors of 0.4 to 0.6 cm in diameter. Beforecoaguligand injection, tumors were healthy, having a uniform morphologylacking regions of necrosis. The tumors were well vascularized and had acomplete absence of spontaneously thrombosed vessels or hemorrhages.Within four hours of coaguligand injection, 40-70% of blood vessels werethrombosed, despite the initial staining of only 20-30% of tumor bloodvessels. The thrombosed vessels contained occlusive platelet aggregates,packed erythrocytes and fibrin. In several regions, the blood vesselshad ruptured, spilling erythrocytes into the tumor interstitium.

By 24 h after coaguligand injection, the blood vessels were stilloccluded and extensive hemorrhage had spread throughout the tumor. Tumorcells had separated from one another, had pyknotic nuclei and wereundergoing cytolysis. By 72 h. advanced necrosis was evident throughoutthe tumor. It is likely that the initial coaguligand-induced thrombindeposition results in increased induction of the VCAM-1 target antigenon central vessels, thus amplifying targeting and tumor destruction.

The thrombotic action of anti-VCAM-1·tTF on tumor vessels was antigenspecific. None of the control reagents administered at equivalentquantities (tTF alone, anti-VCAM-1 antibody alone, tTF plus anti-VCAM-1antibody or the control coaguligand of irrelevant specificity) causedthrombosis.

In addition to the thrombosis of tumor blood vessels, this study alsoshows that intravenous administration of the anti-VCAM-1-tTF coaguliganddoes not induce thrombosis of blood vessels in normal organs. Despiteexpression of VCAM-1 on vessels in the heart and lung of normal or L540tumor-bearing mice, thrombosis did not occur after anti-VCAM-1-tTFcoaguligand administration. No signs of thrombosis, tissue damage oraltered morphology were seen in 25 mice injected with 5 to 45 μg ofcoaguligand 4 or 24 h earlier. There was a normal histologicalappearance of the heart and lung from the same mouse that had majortumor thrombosis. All other major organs (brain, liver, kidney, spleen,pancreas, intestine, testis) also had unaltered morphology.

Frozen sections of organs and tumors from coaguligand-treated mice gavecoincident staining patterns when developed with either the anti-TFantibody, 10H10, or an anti-rat IgG antibody and confirmed that thecoaguligand had localized to vessels in the heart, lung and tumor. Theintensity of staining was equal to that seen when coaguligand wasapplied directly to the sections at high concentrations followed bydevelopment with anti-TF or anti-rat IgG, indicating that saturation ofbinding had been attained in vivo.

These studies show that binding of coaguligand to VCAM-1 on normalvasculature in heart and lung is not sufficient to induce thrombosis,and that tumor vasculature provides additional factors to supportcoagulation.

The anti-tumor activity of anti-VCAM-1·tTF coaguligand was determined inSCID mice bearing 0.3-0.4 cm³ L540 tumors. The drug was administeredi.v. 3 times at intervals of 4 days. Mean tumor volume ofanti-VCAM-1·tTF treated mice was significantly reduced at 21 days oftreatment (P<0.001) in comparison to all other groups. Nine of a totalof 15 mice treated with the specific coaguligand showed more than 50%reduction in tumor volume. This effect was specific since unconjugatedtTF, control IgG coaguligand and mixture of free anti-VCAM-1 antibodyand tTF did not affect tumor growth.

Example II Phosphatidylserine Expression on Tumor Blood Vessels

To explain the lack of thrombotic effect of anti-VCAM-1·tTF on VCAM-1positive vasculature in heart and lungs, certain of the inventorsdeveloped a concept of differential aminophospholipid and anionicphospholipid, e.g. PS and PE, localization between normal and tumorblood vessels. Specifically, they hypothesized that endothelial cells innormal tissues segregate aminophospholipids and anionic phospholipids,e.g. PS and PE, to the inner surface of the plasma membrane phospholipidbilayer, where PS is unable to participate in thrombotic reactions;whereas endothelial cells in tumors translocate aminophospholipids andanionic phospholipids to the external surface of the plasma membrane,where PS can support the coagulation action of the coaguligand. PSexpression on the cell surface allows coagulation because it enables theattachment of coagulation factors to the membrane and coordinates theassembly of coagulation initiation complexes.

The inventors' model of aminophospholipid and anionic phospholipidtranslocation to the surface of tumor blood vessel endothelial cells, asdeveloped herein, is surprising in that PS expression does not occurafter, and does not inevitably trigger, cell death. Aminophospholipidand anionic phospholipid expression at the tumor endothelial cellsurface is thus sufficiently stable to allow aminophospholipids andanionic phospholipids. e.g. PS and PE, to serve as targetable entitiesfor therapeutic intervention.

To confirm the hypothesis that tumor blood vessel endothelium expressesPS on the luminal surface of the plasma membrane, the inventors used thefollowing immunohistochemical study to determine the distribution ofanti-PS antibody after intravenous injection into L540 tumor bearingmice.

A. Methods

Anti-PS and anti-cardiolipin antibodies, both mouse monoclonal IgMantibodies, were produced and characterized by Rote et al. (1993,incorporated herein by reference) as described in Example IV. The majorreactivity of 3SB is with PS, but it also has reactivity with theanionic phospholipid, phosphatidic acid, a relatively minor component ofthe plasma membrane also tightly segregated to the internal leaflet innormal cells.

L540 tumor-bearing mice were injected i.v. with 20 μg of either anti-PSor anti-cardiolipin mouse IgM antibodies. After 10 min., mice wereanesthetized and their blood circulations were perfused with heparinizedsaline. Tumors and normal tissues were removed and snap-frozen. Serialsections of organs and tumors were stained with either HRP-labeledanti-mouse IgM for detection of anti-PS antibody or with anti-VCAM-1antibody followed by HRP-labeled anti-rat Ig.

To preserve membrane phospholipids on frozen sections, the followingprotocol was developed. Animals were perfused with DPBS containing 2.5mM Ca²⁺. Tissues were mounted on 3-aminopropyltriethoxysilane-coatedslides and were stained within 24 h. No organic solvents, formaldehydeor detergents Were used for fixation or washing of the slides. Slideswere re-hydrated by DPBS containing 2.5 mM Ca²⁺ and 0.2% gelatin. Thesame solution was also used to wash sections to remove the excess ofreagents. Sections were incubated with HRP-labeled anti-mouse IgM for3.5 h at room temperature to detect anti-PS IgM.

B. Results

This immunohistochemical study showed that anti-PS antibody localizedwithin 10 min. to the majority of tumor blood vessels, including vesselsin the central region of the tumor that can lack VCAM-1. Vessels thatwere positive for VCAM-1 were also positive for PS. Thus, there iscoincident expression of PS on VCAM-1-expressing vessels in tumors.

In the in vivo localization studies, none of the vessels in normalorgans, including VCAM-1-positive vasculature of heart and lung, werestained, indicating that PS is absent from the external surface of theendothelial cells. In contrast, when sections of normal tissues andtumors were directly stained with anti-PS antibody in vitro, nodifferences were visible between normal and tumor, endothelial or othercell types, showing that PS is present within these cells but onlybecomes expressed on the surface of endothelial cells in tumors.

The specificity of PS detection was confirmed by two independentstudies. First, a mouse IgM monoclonal antibody directed against adifferent negatively charged lipid, cardiolipin, did not home to tumoror any organs in vivo. Second, pretreatment of frozen sections withacetone abolished staining with anti-PS antibody, presumably because itextracted the lipids together with the bound anti-PS antibody.

Example III Annexin V Blocks Coaguligand Activity

The present example provides further evidence of the role of surface PSexpression in coaguligand activity from studies using the high affinityPS binding ligand, annexin V, to block PS function in vitro and in vivo.

A. Annexin V Blocks Coaguligand Activation of Factor X In Vitro

The ability of Annexin V to affect Factor Xa formation induced bycoaguligand was determined by a chromogenic assay. IL-1α-stimulatedbEnd.3 cells were incubated with anti-VCAM-·tTF and permeabilized bysaponin. Annexin V was added at concentrations ranging from 0.1 to 10μg/ml and cells were incubated for 30 min. before addition of dilutedProplex T. The amount of Factor Xa generated in the presence or absenceof Annexin V was determined. Each treatment was performed in duplicateand repeated at least twice.

The need for surface PS expression in coaguligand action is furtherindicated by the inventors' finding that annexin V, which binds to PSwith high affinity, blocks the ability of anti-VCAM-1-tTF bound tobEnd.3 cells to generate factor Xa in vitro.

Annexin V added to permeabilized cells preincubated with anti-VCAM-1·tTFinhibited the formation of factor Xa in a dose-dependent manner. In theabsence of Annexin V, cell-bound coaguligand produced 95 ng of factor Xaper 10,000 cells per 60 min. The addition of increasing amounts ofAnnexin V (in the μg per ml range) inhibited factor Xa production. At 10μg per ml, Annexin V inhibited factor Xa production by 58%. No furtherinhibition was observed by increasing the concentration of Annexin Vduring the assay, indicating that annexin V saturated all availablebinding sites at 10 μg per ml.

B. Annexin V Blocks Coaguligand Activity In Vivo

The ability of Annexin V to inhibit coaguligand-induced thrombosis invivo was examined in L540 Hodgkin-bearing SCID mice. Tumors were grownin mice and two mice per group (tumor size 0.5 cm in diameter) wereinjected intravenously via the tail vein with one of the followingreagents: a) saline; b) 100 μg of Annexin V; c) 40 μg ofanti-VCAM-1·tTF; d) 100 μg of Annexin V followed 2 hours later by 40 μgof anti-VCAM-1·tTF.

Four hours after the last injection mice were anesthetized and perfusedwith heparinized saline. Tumors were removed, fixed with 4% formalin,paraffin-embedded and stained with hematoxylene-eosin. The number ofthrombosed and non-thrombosed blood vessels was counted and thepercentage of thrombosis was calculated.

Annexin V also blocks the activity of the anti-VCAM-1·tTF coaguligand invivo. Groups of tumor-bearing mice were treated with one of the controlor test reagents. The mice were given (a) saline; (b) 100 μg of AnnexinV; (c) 40 μg of anti-VCAM-1·tTF coaguligand; or (d) 100 μg of Annexin Vfollowed 2 hours later by 40 μg of anti-VCAM-1·tTF coaguligand.Identical results were obtained in both mice per group.

No spontaneous thrombosis, hemorrhages or necrosis were observed intumors derived from saline-injected mice. Treatment with Annexin V alonedid not alter tumor morphology.

In accordance with other data presented herein, 40 μg of anti-VCAM-1·tTFcoaguligand caused thrombosis in 70% of total tumor blood vessels. Themajority of blood vessels were occluded with packed erythrocytes andclots, and tumor cells were separated from one another. Bothcoaguligand-induced anti-tumor effects, i.e., intravascular thrombosisand changes in tumor cell morphology, were completely abolished bypre-treating the mice with Annexin V.

These findings confirm that the anti-tumor effects of coaguligands aremediated through the blockage of tumor vasculature. These data alsodemonstrate that PS is essential for coaguligand-induced thrombosis invivo.

Example IV Generation of Antibodies to Aminophospholids and AnionicPhospholipids

This example describes an immunization protocol designed by theinventors in light of their observations on aminophospholipid andanionic phospholipid translocation in tumor vascular endothelial cells,and discovered to function well in the generation of antibodies againstaminophospholipids and anionic phospholipids. A number of antibodiesreactive with aminophospholipids and anionic phospholipids, such as PSand PE, were obtained. In the present and following examples, forsimplicity, antibodies reactive with PS can be termed “anti-PSantibodies”, although the binding of certain of these antibodies is notrestricted to PS but extends to certain other aminophospholipids andanionic phospholipids as shown herein.

A. Immunization Protocol

To present aminophospholipids and anionic phospholipids to the immunesystem as stronger immunogens, the aminophospholipids and anionicphospholipids were formulated as aminophospholipid-positive and anionicphospholipid-positive cells. The membrane-inserted aminophospholipidsand anionic phospholipids, surrounded by other membrane components, havea better conformation and clearance rate for raising antibodies.

The intent is to immunize immunocompetent animals with autologous cellsexpressing aminophospholipids and anionic phospholipids, as exemplifiedin this instance by PS, wherein the animals would not produce antibodiesagainst all self surface antigens, but would recognize membrane-exposedphospholipids, e.g. PS, as a foreign element. The procedure isapplicable to the use of any standard laboratory animals, such asimmunocompetent BALB/c mice and Lewis rats, with anyaminophospholipid-positive or anionic phospholipid-positive cells.

BALB/c mice and mouse endothelioma cells, bEnd.3 (immortalized mouse(BALB/c strain) endothelial cells), were first chosen, bEnd.3 werecultured in 10% DMEM with 9 ml/500 ml HEPES Buffer, in 10% CO₂incubator. The bEnd.3 cells were expanded in TI 75 TC flasks until thedesired number of cells were obtained. Typically, each flask at ˜70-80%confluency has about 3×10° cells, and each mouse should receive from1×10⁶ to 20×10⁶ cells, up to 1×10⁷ cells.

bEnd.3 cells are treated with 50 μM to 200 μM of hydrogen peroxide for 1or 2 hours at 37° C. to expose anionic phospholipids, such as PS, beforeimmunization. The stock of H₂O₂ is [9.8M]; 30% (v/v). This is diluted1:1000, then 0.4 ml is add into the T175 TC flask with 40 ml media to afinal concentration of 100 μM H₂O₂. The cells were maintained for 1 hourat 37° C. To harvest, the cells were washed 3× with warm PBS, +10 mMEDTA, to remove all BSA or serum protein in the medium. The cells wereremove with gentle trypsin treatment, washed and centrifuged for 5minutes at 1000 rpm. The supernatant was aspirated and the cellsresuspended in DMEM without additives to the appropriate volume (eachmouse receives about 1×10⁷ cells in 200 μl) and kept on ice.

Cells treated in this manner were injected (200 μl of cell suspension)into each mouse IP using 1 ml syringe and 23 gauge needle. Mice wereimmunized from three to seven times at intervals of 3 to 4 weeks. Immunesera were collected by bleeding the mice ten days after each boost,starting from the second boost. The serum titer for anti-PS was testedby ELISA.

These immunizations with autologous PS-positive cells did not result inunrestricted production of autoantibodies, but were limited to theproduction of antibodies reactive with PS or reactive with PS incombination with other aminophospholipids and anionic phospholipids.

In another study, female Lewis rats were immunized with bEnd.3endothelial cells that had been treated with 200 μM of hydrogen peroxidefor 2 h. The treatment caused translocation of anionic phospholipids tothe external surface in 70-90% of cells as detected by ¹²⁵I-labeledannexin V. Treated cells were washed, detached and counted. Two millioncells were suspended in sterile PBS and injected 5 times i.p. with theinterval of 3 wk between injections. The titer of polyclonal antibodiesto anionic phospholipids was determined 2 days after each immunization.

B. High Titer Antisera

Mice with extremely high titers of antibodies reactive with anionicphospholipids such as PS were obtained (Table 1). The mice did not showany signs of toxicity. Although this immunization protocol was moreeffective in mice than rats overall, immunization of rats was effectiveand produced the 9D2 antibody (see below).

TABLE 1 Anti-PS IgG Antibody Generation Number of Mice per Group TiterRange (% of total) 1:100-1:1,000  2/30 (6.66%) 1:1000-1:10,000  5/30(16.6%) 1:10,000-1:100,000   18/30 (60%) 1:100,000-1,000,000    5/30(16.6%)

In further immunizations, various mice were immunized three times withhydrogen peroxide-treated bEnd.3 cells and the serum was tested 54 daysafter the first immunization. IgG antibodies reactive with PS withinserum were detected with an anti-mouse IgG. Fc specific secondaryantibody, and IgM antibodies within serum were detected with ananti-mouse IgG mu specific secondary antibody. A number of effectiveantisera with IgG and IgM antibodies reactive with PS were obtainedusing this immunization protocol, of which the antisera with IgGantibodies were generally more effective.

These methods can now be used to generate further particular anti-PSantibodies, e.g., including those screened for effectively competitionwith the 3G4 antibody described below. Typically, when the IgG titer ofthe desired antisera for PS reaches >200,000, but PC titer is <50,000,fusion can be performed to generate the monoclonal antibody.

Also, these methods are not limited to initial cell treatment with H₂O₂,as other methods to induce expression of aminophospholipids and anionicphospholipids can be used. For example, treatment with TNF andactinomycin D is another useful method. In one case, subconfluent (˜85%confluence) bEnd. 3 cells were treated with 10 ng/ml mouse TNF and 1μg/ml actinomycin D for 16 hrs at 37° C. in the incubator. The cellswere then taken through the immunization procedure as outlined above.

C. IgG and IgM Monoclonal Antibodies

Hybridomas were obtained by fusing splenocytes from immunized animalswith myeloma partner P3X63AG8.653 cells (ATCC, Rockville, Md.).

An important aspect of the inventors' technique to prepare monoclonalantibodies useful in tumor treatment is the selection strategy, whichinvolves screening to select antibodies that bind to aminophospholipidsor anionic phospholipids, but not to neutral phospholipids. A certainaspect is to select antibodies that bind to PS-coated plates as stronglyin the presence of serum as in the absence of serum.

The strategy to isolate monoclonal antibodies reactive with PS, forexample, involved screening hybridoma supernatants on PS-coated platesusing an anti-mouse IgG, Fc gamma specific secondary antibody. Screeningwas first conducted against four phospholipids (PS, phosphatidylserine;PE, phosphatidylethanolamine; CL, cardiolipin; and PC,phosphatidylcholine), as well as bEnd3 cells. Clones reactive with theneutral phospholipid, PC were discarded, as were clones non-reactivewith bEnd3 cells. High binding anti-PS clones were selected. The wellsthat had PS only reactivity, or strong preference for PS were sub-clonedfirst, and wells that exhibited PS reactivity in combination withbinding to other anionic phospholipids were sub-cloned second.

In certain in the following studies, mouse monoclonal IgM antibodiestermed 3SB, D11 and BA3, produced as described by Rote et al. (1993),were also included. The 3SB antibody is described in the literature asan anti-PS antibody and the D11 antibody is described in the literatureas an anti-cardiolipin (anti-CL) antibody. Details of the generation andcharacterization of these antibodies were reported by Rote et al. (1993,incorporated herein by reference).

The isotype of each selected hybridoma generated by the inventors wasdetermined. As antibodies of IgG class have numerous advantages overIgM, including typically higher affinity, lower clearance rate in vivoand simplicity of purification, modification and handling, theirgeneration was particularly desired. To focus on wells with homogeneousIgG isotype wells containing IgM or a mixture of different Igs werediscarded or re-cloned. Sub-cloning of highly positive clones wasrepeated three to four times.

The isotype of representative IgG and IgM antibodies, as determined byELISA, is shown in Table 2. The inventors initially termed the 3G4antibody “F3-G4”, before changing the designation to 3G4. This does noreflect any change in biological material. The serum dependence orindependence of the antibodies is also set forth in Table 2.

TABLE 2 Isotype and Serum-Dependence of Anti-PS Antibodies Serum- NameOrigin Species/Isotype dependence 3SB Rote et al., 1993 Mouse IgM kappaNone D11 N. Rote Mouse IgM kappa BA3 Rote et al., 1993 Mouse IgM kappa9D2 This study Rat IgM kappa None 1B12 This study Mouse IgG₁ kappa 3G4This study Mouse IgG₃ kappa Yes 1B9 This study Mouse IgG₁ kappa Absolute3B10 This study Mouse IgG₃ kappa Yes 2G7 This study Mouse IgG₁ kappaAbsolute 7C5 This study Mouse IgG₁ kappa AbsoluteD. ELISA Protocol and Monoclonal Antibody Characterization

The antibodies were studied further by ELISA and compared to 3SB andD11. The anti-PS ELISA used in the present studies is conducted asfollows. Unless particular differences are specified, this is the formatof the ELISA used throughout the studies of the present application.

The ELISA is exemplified using the antigen PS(P-6641 25 mg 10 mg/ml(solvent is Chloroform:MeOH 95:5) in 2.5 ml bottle). Other phospholipidscan be used using the same protocol. The PS (or other phospholipids)stock solution should be aliquoted and stored in an airtight containerat −30° C. The preferred 96 well plates are Dynatech U bottom Immulon 1(from Dynatech Labs Cat# 011-010-3550).

The standard blocking buffer used herein is 10% bovine serum dissolvedin PBS. Other blocking solutions are suitable, but any detergents shouldbe excluded from block and wash solutions. The primary antibody is thetest sample or admixture. The preferred secondary antibody is goat,anti-mouse IgG-HRP. The developing solutions are: 10 ml of 0.2 M Na₂PO₄,10 ml of 0.1M citric acid, one 10 mg tablet of OPD, and 10 μl ofhydrogen peroxide. The stop solution is 0.18 M H₂SO₄.

The protocol entails coating 96-well plate with PS as follows: dilutethe PS stock solution in n-hexane to 10 μg/ml and mix well. Add 50 μl toeach well and allow this to evaporate for one hour. Add 200 μl of 10%serum (or other blocking buffer) to each well, cover and maintain atroom temperature for 2 hours or overnight at 4° C. Wash the plate threetimes with PBS. Add the primary antibody (dilute in blocking buffer) andincubate for 2 hours at 37° C. Wash three times with PBS. Add 100μl/well of secondary antibody (typically goat, anti-mouse IgG-HRP orother appropriate secondary antibody) and incubate for 1 hour at 37° C.Wash the plate three times with PBS. Develop the ELISA by adding 100 μlof developing solution to each of the wells, develop for 10 minutes,then add 100 μl of stop solution to each plate and read the O.D. at 490nm.

The following results are presented for 9D2, 1B 12, 3G4 and 1B9. Theaffinity of these antibodies for PS was determined and compared to 3SB.Certain of the relative affinities of the new antibodies are muchimproved compared to 3SB (Table 3).

TABLE 3 Relative Affinity of Anti-PS Antibodies EC₅₀ Binding vs. 3SBEC₅₀ Affinity vs. 3SB Name (μg/ml)¹ (-fold increased) (nM)² (-foldincreased) 3SB 0.468 1 0.518 1 D11 >40.0 0.011 >44.4 0.011 9D2 0.1044.50 0.115 4.50 1B12 0.312 1.50 2.07 0.25 3G4 0.040 11.7 0.266 1.94 1B90.019 24.6 0.126 4.11 Annexin V³ 0.100 4.68 2.77 0.18 ¹Based ondilutions of Tissue Culture supernatants; concentration of IgG and IgMwere determined by sandwich ELISA using either anti-mouse or rat Igs ascapturing Antibodies. All clones secrete in average 10 to 15 μg/ml ofIg. ²MW used for conversion: IgM - 900 kDa, IgG - 150 kDa, Annexin V -36 kDa ³Affinity of Annexin V to PS is in the range of 0.1 nM to 1 nM.The value in this table represents binding of commercial biotinylatedAnnexin V detected by streptavidin-HRP using the same ELISA conditionsas for anti-PS antibodies.

The specificity of the antibodies was determined by ELISA using platescoated with the following phospholipids: PS, phosphatidylserine; PE,phosphatidylethanolamine; PI, phosphatidylinositol: PA, phosphatidicacid; PG, phosphatidylglycerol; PC, phosphatidylcholine: CL,cardiolipin; and SM, sphingomyelin. The specificity profiles of 9D2,1B12, 3G4 and 1B9, as compared to 3SB and D11, are shown in Table 4.

TABLE 4 Phospholipid Specificity of Anti-PS Antibodies Relative Strengthof Name Reactivity on ELISA^(1,2) 3SB PS = PA >> CL, PI, PE, PG D11 CL =PA >> PS, PI, PE, PG 9D2 PA > PS = CL > PG = PI >> PE 1B12 PS = PA >CL > PE = PI, PG 3G4 PS = PA = PI = PG = CL >> PE 3B10 PS = PA = PI >>PE 1B9 PS only 2G7 PS only 7C5 PS only Annexin V PS = PE = PI = PA >CL > PG ¹The symbol > indicates at least 2-fold difference in binding tovarious phospholipids tested at identical antibody concentration. ²Thesymbol >> indicates at least 10-fold difference in binding to variousphospholipids tested at identical antibody concentration.

The 1B9, 2G7 and 7C5 antibodies behave essentially the same. Theseantibodies recognize only PS and require serum or serum proteins forbinding to PS. The binding of 1B9, 2G7 and 7C5 to various phospholipidswas assayed only in the presence of 10% bovine serum, whereas binding ofthe other antibodies was tested either in the absence or in the presenceof serum. For the 9D2 antibody, the presence of serum does not changepreference in binding to a particular phospholipid. The 9D2 antibodybinds to PS in the absence of serum.

The 3SB antibody recognizes PS on intact cells in the presence andabsence of serum. The major reactivity of 3SB is with PS, but it alsohas reactivity with phosphatidic acid, which is a relatively minorcomponent of the plasma membrane (Hinkovska-Galcheva et al., 1989). 3SBis essentially devoid of reactivity with phosphatidylethanolamine andphosphatidylinositol, as well as phosphatidylcholine and sphingomyelin(Table 4).

PS is the most abundant anionic phospholipid of the plasma membrane andis tightly segregated to the internal leaflet of the plasma membrane innormal cells under normal conditions. PS is an aminophospholipid. PE isalso an aminophospholipid, but PE is neutral, not anionic. Other thanbeing a neutral aminophospholipid, PE behaves similarly to PS and isnormally tightly segregated to the internal leaflet of the plasmamembrane.

PI is another major anionic phospholipid of the plasma membrane, whichis further tightly segregated to the internal leaflet in normal cellsunder normal conditions. PA and PG are minor anionic phospholipids ofthe plasma membrane, which are also normally segregated to the internalleaflet. CL is an anionic phospholipid present in mitochondrialmembranes, and typically absent from the plasma membrane.

PC and SM are choline-containing, neutral phospholipids of the plasmamembrane. Each of PC and SM are predominantly located on the externalleaflet under normal conditions.

In keeping with the inventors' model for differential aminophospholipidand anionic phospholipid expression between normal and tumor bloodvessels, none of the antibodies developed using the selected protocolreacted with the neutral phospholipids, PC and SM. The 1B9 antibody wasspecific for PS, whereas 9D2, 1B12 and 3G4 bound to anionicphospholipids and aminophospholipids with the preferences shown in Table4. The 9D2 antibody is also described in Example VI.

Example V Externalized Phosphatidylserine is a Global Marker of TumorBlood Vessels

The present example shows that the exposure of PS occurs on endothelialcells in each of ten different solid tumors growing in mice and is notlimited to the L540 tumor model described in Example II.

Externalized PS in vivo was detected by injecting a monoclonal antibodydirected against PS intravenously into mice bearing various types ofhuman or murine tumors. Anti-PS antibodies are shown to bindspecifically to vascular endothelium in all ten different tumor models.Vascular endothelium in normal organs derived from the same mice wereunstained. An isotype-matched control monoclonal antibody did notlocalize to either tumor or normal cells. Apoptotic cells were alsoidentified immunohistochemically, wherein very few endothelial cells intumors expressed markers of apoptosis.

The present example therefore shows that vascular endothelial cells intumors but not in normal vessels externalize PS. Most of the tumorendothelial cells having exposed PS were not apoptotic. PS is thus anabundant and accessible marker of tumor vasculature that can be used fortumor vessel imaging and therapy.

A. L540, H358 and HT29 Tumors

The anti-PS antibody used in these studies was the mouse monoclonal IgMantibody termed 3SB (Example IV, Rote et al., 1993). 3SB mainly binds toPS, but also reacts with PA, a relatively minor anionic phospholipidwith a distribution like PS. The anti-CL antibody used was the mousemonoclonal IgM antibody termed D11 (Example IV, Rote et al., 1993).

PS exposure on tumor and normal vascular endothelium was first examinedin three animal tumor models: L540 human Hodgkin's lymphomas, NCI H358human non-small cell lung carcinoma (NSCLC) and HT29 human colorectalcarcinomas. To grow the tumors in vivo. 2×10⁶ cells were injected intothe right flank of SCID mice and tumors allowed to reach 0.8-1.2 cm indiameter.

Mice bearing large tumors (volume above 800 mm³) were injectedintravenously via the tail vein with 20 μg of either anti-PS or anti-CLantibodies. One hour after injection, mice were anesthetized and theirblood circulation was perfused with heparinized saline. Tumors andnormal organs were removed and snap-frozen for preparation ofcryosections. Mouse IgM was detected using goat anti mouse IgM (μspecific)-HRP conjugate followed by development with carbazole. At least10 random fields per section were examined at ×40 magnification and theaverage percentage of positive vessels was calculated.

The anti-PS antibodies specifically homed to the vasculature of allthree tumors (HT 29. L540 and NCI-H358) in vivo, as indicated bydetection of the mouse IgM. In this first study, the average percentagesof vessels stained in the tumors were 80% for HT 29.30% for L540 and 50%for NCI-H358. Vessels in all regions of the tumors were stained andthere was staining both of small capillaries and larger vessels.

No vessel staining was observed with anti-PS antibodies in any normaltissues. In the kidney, tubules were stained in both anti-PS and anti-CLrecipients, and this relates to the secretion of IgM through this organ.Anti-CL antibodies were not detected in any tumors or normal tissues,except kidney. These findings indicate that only tumor endotheliumexposes PS to the outer site of the plasma membrane.

B. Small and Large L540 Tumors

To estimate the time at which tumor vasculature loses the ability tosegregate PS to the inner side of the membrane, anti-PS localization wasexamined in L540 tumors ranging in volume from 140 to 1,600 mm³.

Mice were divided into 3 groups according to their tumor size: 140-300,350-800 and 800-1,600 mm³. Anti-PS Ab was not detected in three micebearing small L540 tumors (up to 300 mm³). Anti-PS Ab localized in 3animals of 5 in the group of intermediate size L540 tumors and in allmice (4 out of 4) bearing large L540 tumors (Table 5). Percent ofPS-positive blood vessels from total (identified by pan endothelialmarker Meca 32) was 10-20% in the L540 intermediate group and 20-40% inthe group of large L540 tumors (Table 5).

TABLE 5 PS Externalization Detected in Mid and Large Sized Tumors TumorSize No. Positive % PS-Positive (mm³) Tumors/Total* Vessels/Total†350-800 3/5 10-20 850-1,600 4/4 20-40 *Mice bearing L540 Cy tumors weredivided into three groups according to tumor size. 20 μg of anti-PSantibodies were injected i.v. and allowed to circulate for 1 hour. Mouseantibodies were detected on frozen sections using anti-mouseIgM-peroxidase conjugate. †Total number of blood vessels was determinedusing pan-endothelial Ab Meca 32. PS-positive and Meca-positive vesselswere counted in 4 fields per cross section of tumor. Range of %PS-positive vessels within the same group is shown.C. L540, H358, HT29, Colo26, B16 and 3LL Tumors

Using the same anti-PS (3SB) and anti-CL (D11) antibodies, PS exposureon tumor and normal vascular endothelium was examined in further studiesusing an additional three animal tumor models (six in total): L540 humanHodgkin's lymphomas, NCI H358 human non-small cell lung carcinoma(NSCLC), HT29 human colorectal carcinomas, Colo26 mouse coloncarcinomas, B 16 mouse melanomas and 3LL mouse lung tumors.

In these studies, tumors were grown subcutaneously in SCID mice andallowed to reach a volume of 0.4-0.7 cm³. Three or more mice were usedper group. Anti-PS or anti-CL mouse IgM antibodies (30 μg/mouse) wereinjected intravenously in 200 μl of saline. Thirty minutes later, themice were sacrificed, exsanguinated and their blood circulation perfusedwith heparinized saline. Major organs and tumors were harvested andsnap-frozen for preparation of cryosections. Mouse IgM was detectedusing goat anti mouse IgM (μspecific)-HRP conjugate followed bydevelopment with carbazole.

Serial sections of tumor were stained with a monoclonal antibody. MECA32, directed against a pan-endothelial marker of mouse vessels.PS-positive vessels were identified morphologically and by theircoincident staining with anti-mouse IgM and MECA 32. At least 10 randomfields per section (0.317 mm²/field) were examined in blinded fashion bytwo independent observers. The percentage of MECA 32-positive vesselsthat stained positively for PS was calculated. Three tumors of each typewere examined in each of two separate studies. The mean values andstandard errors (SE) were calculated. Inter-tumor variation in thenumber of total and PS-positive vessels in each group was approximately10%.

All six tumors in this study contained PS-positive vessels (Table 6).Detection of PS by 3SB was specific since no staining of tumorendothelium was observed with the anti-CL antibody (Table 6; FIG. 1). Novascular localization of anti-PS or anti-CL antibodies was observed innormal organs other than the kidneys (tubule staining in both anti-PSand anti-CL recipients reflects secretion of IgM through this organ).

TABLE 6 Specific Localization of Anti-PS Antibodies to Tumor VesselsTissue Anti-PS* Anti-CL L540 tumor 19.3 ± 3.3 0 H358 tumor 15.6 ± 4.1 0HT29 tumor  4.2 ± 1.6 0 B16 tumor 40.6 ± 5.4 0 3LL tumor  5.3 ± 3.7 0Colo 26 tumor 12.4 ± 2.4 0 Adrenal 0 0 Brain 0 0 Heart 0 0 Kidney 0^(†)0^(†) Intestine 0 0 Liver 0 0 Lung 0 0 Pancreas 0 0 Spleen 0 0 Testis 00 *The results are presented as the mean (±SE) percentage of PS-positivevessels of MECA 32-stained vessels per field of 0.317 mm². Six tumors ofeach type were analyzed. The average number of MECA 32-positive vesselsper 0.317 mm² field was 25, 21, 17, 18, 27 and 22 ± 10% vessels forL540, H358, HT29, B16, 3LL and Colo 26 tumors, respectively^(†)Non-antigen specific tubular staining was visible in both anti-PSand anti-CL recipients.

In these studies, the percentage of PS-positive vessels ranged from 10%in Colo 26 tumors to 40% in B 16 tumors. Anti-PS IgM was present on theluminal surface of capillaries and venules in all regions of the tumors.PS-positive vessels appeared to be particularly prevalent in and aroundregions of necrosis. Positive vessels usually did not show morphologicalabnormalities that were apparent by light microscopy. Occasional vesselslocated in necrotic areas showed morphological signs of deterioration.Anti-PS antibody (but not anti-CL antibody) also localized to necroticand apoptotic tumor cells.

These controlled studies demonstrate that PS is consistently exposed onthe luminal surface of vascular endothelial in various tumors, but notin normal tissues, and that the tumor vasculature expression is notmodel-specific.

D. The Majority of PS-Positive Tumor Vessels are Not Apoptotic

A double labeling technique was used to identify apoptotic endothelialcells in tumor sections. Endothelial cells were identified with thepan-endothelial cell marker, MECA 32. Apoptotic cells were identifiedimmunohistochemically using two independent markers: an active form ofcaspase-3, which identifies cytosolic changes in dying cells (Krajewskaet al. 1997), and fragmented DNA, which identifies cells having nuclearalterations (Gavrieli et al. 1992).

Active caspase-3 was detected by a rabbit anti-caspase-3 specificantibody (R&D. Minneapolis, Minn.) followed by incubation withanti-rabbit IgG conjugated to alkaline phosphatase (AP, Pierce,Rockford, Ill.). Other tumor sections were analyzed by Tunel assay(ApopTag™ kit, Oncor, Md.) using anti-digoxigenin-alkaline phosphataseconjugate as a detecting reagent. Sections were double stained forapoptosis markers (pink) and the endothelial cell marker, MECA 32(brown). Both colors were clearly visible on the same cells, if markersof endothelial cells and apoptotic cells coincided.

Endothelial cells in five out of six types of tumors (HT29, H358, B16,Colo 26, L540) did not display either of the apoptosis markers (Table7). The sixth type of tumor, 3LL, displayed a few apoptotic endothelialcells that were located in necrotic areas. In contrast, apoptoticmalignant cells were common in all types of tumors. The percentage ofapoptotic tumor cells ranged from 1-2% in L540 tumors to 12.6-19.6% in3LL tumors.

TABLE 7 Expression of Apoptotic Markers in Tumors Active caspase-3 Tunelassay Tumor cells Tumor Tumor cells Tumor Tumor type (% of total)*vessels (% of total) vessels 3LL 19.8 ± 4.3  <1.0^(†) 12.6 ± 3.6  0 HT2913.7 ± 2.3  0 7.8 ± 2.5 0 H358 5.8 ± 2.0 0 4.3 ± 1.6 0 Colo 26 5.3 ± 1.50 4.1 ± 1.5 0 B16 4.2 ± 1.8 0 3.5 ± 1.6 0 L540 2.3 ± 1.0 0 1.6 ± 0.5 0*The percentage of tumor cells or tumor blood vessels that were positivefor either caspase-3 or Tunel was determined in ten high power fieldsper section. The fields were randomly selected along two perpendiculardirections from the edges through the center of the tumor. The mean(±SE) of the percentage of positive cells or vessels in tumors from 6mice is presented. ^(†)Occasional vessels (1 of >100) in the necroticarea of 3LL tumor displayed both markers of apoptosis.E. MDA-MB-231 and Meth A Tumors

PS exposure on tumor vascular endothelium was also examined inMDA-MB-231 human breast tumors growing in mice and in mouse Meth Afibrosarcoma growing subcutaneously. The antibody used in these studieswas the 9D2 antibody, generated as described in Example IV, which isreactive with anionic phospholipids.

As described in detail in Example VI, 9D2 localized to tumor vessels inL540. NCI-H358 and B16 tumors, as well as in models of MDA-MB-231 breasttumor growing orthotopically in the mammary fat pads of SCID mice andmouse Meth A fibrosarcoma growing subcutaneously. 9D2 localized to tumorvessels in all of five tumors. Vascular endothelium in the tumors showeddistinct membrane staining. 9D2 antibody also localized to the membraneand cytosol of necrotic and apoptotic tumor cells. No vascularlocalization of 9D2 antibody was observed in 9 of the 10 normal organsthat were examined, with non-specific staining of the tubules in thekidney being observed.

Double-staining studies were also performed in which mice bearingorthotopic MDA-MB-231 breast tumors were injected i.v. with biotinylated9D2 antibody and frozen sections later stained with FITC-conjugatedMECA32 (Example VI). About 40% of MECA 32-positive vessels bound 9D2.

F. MD-MBA435 Tumors

In a further breast cancer model, PS exposure on tumor vascularendothelium was examined in MDA-MB-435 human breast cancer cells growingin mice. The antibody used in these studies is a chimeric version of the3G4 antibody (ch3G4). The 3G4 antibody generation is described inExample IV, and the production of the chimeric 3G4 antibody is detailedin Example XIX. The localization of ch3G4 to tumor vascular endotheliumin the MDA-MB-435 model is described in more detail in Example XIX andshown in FIG. 22.

Briefly, tumors were established using MD-MBA-435s cells andbiotinylated versions of the chimeric 3G4 antibody and a control IgG ofirrelevant specificity were administered. Tumor sections were stainedwith Cy3-conjugated streptavidin to detect the biotinylated proteins.Double staining with the MECA 32 antibody followed by FITC-taggedanti-rat IgG secondary antibody was conducted to detect vascularendothelium. This detection method labeled the biotinylated proteins andthe vascular endothelium using red and green, so that biotinylatedproteins bound to the endothelium appear yellow in a converged image(FIG. 22). This study showed specific localization of the chimeric 3G4antibody to tumor vascular endothelium.

G. RIP-Tag Tumors

For the tenth model, PS exposure on tumor vascular endothelium wasexamined in a “RIP-Tag” transgenic mouse model (RIP1-Tag 2) ofmultistage carcinogenesis. In this transgenic mouse model, every mousedevelops islet tumors of the pancreas by 12-14 weeks of age as a resultof expression of the SV40 T antigen (Tag) oncogene in insulin-producingbeta-cells. Tumors develop in multiple stages from hyper-proliferativeislets, and require an angiogenic switch in order to progress towardsmalignancy. Matrix metalloprotinase-9 controls the angiogenic switch(REF).

9D2 localization studies were conducted in the RIP1-Tag2 model incollaboration with Dr. Donald McDonald, Professor of Pathology at UCSF.9D2 was injected intravenously into RIP1-Tag2 mice starting at 10 weeksof age, when all mice have small, highly vascularized, solid tumors.Double staining of thick (80 μm) tumor sections was performed toidentify localized 9D2 and CD31 in tumors and normal pancreas.Approximately 50% of vessels (CD31 positive) in pancreatic tumors hadlocalized 9D2, whereas vessels in normal islets were unstained. Miceinjected with control rat IgM had weak and infrequent staining of tumorvessels. Some leakage of 9D2 and control rat IgM into extravasculartissues beyond the endothelium was also apparent.

The present example therefore confirms that vascular endothelial cellsin tumors externalize PS and anionic phospholipids to their luminalsurface, where they can be bound by anti-PS antibodies in vivo. PS isabsent from the external surface of vascular endothelial cells in normaltissues, indicating that PS-recognizing antibodies, annexin V and otherligands can be used for delivering cytotoxic drugs, coagulants andradionuclides for the selective imaging or destruction of vessels insolid tumors.

PS-positive tumor endothelium appeared, for the most part, to be viablein the tumors used in this study. It does not display markers ofapoptosis, it is morphologically intact and metabolically active, asindicated by its expression of VCAM-1, E-selectin and other rapidlyturned-over proteins. Although often regarded as an indicator ofapoptosis, PS exposure has been observed in several types of viablecells, including malignant cells (Rao et al., 1992), (Utsugi et al.,1991) activated platelets (Rote et al., 1993), and embryonictrophoblasts at various stages of migration, matrix invasion and fusion(Adler et al., 1995).

Lack of correlation between PS exposure and commitment to cell death hasbeen also shown on pre-apoptotic B lymphoma cells that restore PSasymmetry and grow normally after removal of the pro-apoptotic stimulus(Hammill et al., 1999). In normal viable cells, PS exposure is probablytriggered by surface events, such as ligand-receptor interactions, thatinduce Ca²⁺ fluxes into the cells (Dillon et al., 2000). Ca²⁺ fluxesactivate scramblase (Zhao et al., 1998) and simultaneously inhibitaminophospholipid translocase (Comfurius et al. 1990).

PS on tumor vessels is attractive as a target for cancer imaging ortherapy for several reasons: it is abundant (approximately 3×10⁶molecules per cell); it is on the luminal surface of tumor endothelium,which is directly accessible for binding by vascular targeting agents inthe blood; it is present on a high percentage of tumor endothelial cellsin diverse solid tumors, and it is absent from endothelium in all normaltissues examined to date. Unconjugated antibodies, vascular targetingagents and imaging agents directed against PS or tumor vasculature cantherefore be used for the detection and treatment of cancer in man.

Example VI Anionic Phospholipids are Exposed on the Surface of TumorBlood Vessels

Anionic phospholipids are largely absent from the external leaflet ofthe plasma membrane of mammalian cells under normal conditions. Exposureof phosphatidylserine, for example, on the cell surface occurs duringapoptosis, necrosis, cell injury, cell activation and malignanttransformation. The present example shows that anionic phospholipids areupregulated on tumor vasculature in vivo, as demonstrated bylocalization of both a specific antibody and a natural ligand that bindsto anionic phospholipids.

A monoclonal antibody, 9D2, which specifically recognizes anionicphospholipids, was injected into mice bearing a variety of orthotopic orectopic tumors. Other mice received annexin V, a natural ligand thatbinds to anionic phospholipids. Both 9D2 and annexin V specificallylocalized to vascular endothelium in all tumors and also to tumor cellsin and around regions of necrosis. Between 15 and 40% of endothelialcells in tumor vessels were stained. No localization was detected onnormal endothelium.

Various factors and tumor-associated conditions known to be present inthe tumor microenvironment Were examined for their ability to causeexposure of anionic phospholipids in cultured endothelial cells, asjudged by 9D2 and annexin V binding. Hypoxia/reoxygenation, acidity,thrombin and inflammatory cytokines all induced exposure of anionicphospholipids. Hydrogen peroxide was also a strong inducer. Combinedtreatment with inflammatory cytokines and hypoxia/reoxygenation hadgreater than additive effects. The demonstrated exposure of anionicphospholipids on tumor endothelium in vivo is thus likely to be causedby injury and activation by cytokines and reactive oxygen species.Irrespective of the mechanism, anionic phospholipids are markers oftumor vessels that can now be used for tumor vessel targeting, imagingand therapy.

A. Materials and Methods

1. Materials

Na¹²⁵I was obtained from Amersham (Arlington Heights, Ill.). Dulbecco'smodified Eagle's tissue culture medium and Dulbecco PBS containing Ca²⁺and Mg²⁺ were obtained from Gibco (Grand Island, N.Y.). Fetal calf serumwas obtained from Hyclone (Logan, Utah). L-α-phosphatidylserine,L-α-phosphatidylcholine, cardiolipin, L-α-phosphatidylethanolamine,L-α-phosphatidylinositol, sphingomyelin, phosphatidic acid,phosphatidylglycerol, O-phenylenediamine, hydrogen peroxide and thrombinwere from Sigma (St. Louis, Mo.). Flat bottom plates with 24 wells wereobtained from Falcon (Becton Dickinson and Co., Lincoln Park, N.J.).

Recombinant hepatocyte growth factor (HGF or scatter factor) andactinomycin D was from Calbiochem (San Diego, Calif.). Recombinantmurine interleukin-1 alpha, beta and tumor necrosis facto, alpha (TNF α)were purchased from R&D Systems (Minneapolis, Minn.). Interferon ofUniversal Type I (hybrid protein that substitutes for all types ofinterferons) was purchased from PBL Biomedical Laboratories (NewBrunswick, N.J.). Recombinant human vascular endothelial growth factor121 (VEGF), human platelet-derived growth factor-BB, interleukin-6(IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10) and humanfibroblast growth factor-2 (FGF-2) were purchased from PeproTech (RockyHill, N.J.).

2. Antibodies

MECA 32, a pan mouse endothelial cell antibody, was obtained from Dr. E.Butcher (Stanford University, Calif.) and served as a positive controlfor immunohistochemical studies. Details of this antibody have beenpublished (Leppink et al., 1989). Rabbit anti-rat immunoglobulin,rat-anti mouse immunoglobulin and goat-anti mouse and anti-rat secondaryantibodies conjugated to horseradish peroxidase (HRP) were purchasedeither from Daco (Carpinteria, Calif.) or from Jackson ImmunoresearchLabs (West Grove, Pa.).

The 9D2 antibody used in these studies was generated as described inExample IV. 9D2 is a rat monoclonal antibody reactive with anionicphospholipids. Further characterization of the phospholipid specificityof 9D2 is given in the results section of this example.

3. Cells

L540Cy Hodgkin lymphoma cells, derived from a patient with end-stagedisease, were provided by Prof. V. Diehl (Köln, Germany). NCI-H358 humannon-small cell lung carcinoma was provided by Dr. Adi Gazdar(Southwestern Medical Center, Dallas, Tex.). Meth A mouse fibrosarcomaand MDA-MB-231 human breast carcinoma were obtained from American TypeCell Collection (Rockville, Md.). The mouse brain endothelioma line,bEnd.3, was provided by Prof. Werner Risau (Max Plank Institution,Munich, Germany) and was maintained in DMEM with 10% FBS. Adult bovineaortic endothelial (ABAE) cells were purchased from Clonetics (SanDiego, Calif.; Walkerville, Md.). ABAE cells were maintained in DMEMwith 10% serum and 2 ng/ml of bFGF.

4. Tissue Culture

bEnd.3. ABAE cells and all tumor cells except L540Cy lymphoma weremaintained in DMEM supplemented with 10% fetal calf serum, 2 mML-glutamine, 2 units/ml penicillin G and 2 μg/ml streptomycin. L540Cycells were maintained in RPMI 1640 containing the same additives. Cellswere sub-cultured once a wk. Trypsinization of bEnd.3 cells wasperformed using 0.125% trypsin in PBS containing 0.2% EDTA. For in vitrostudies, endothelial cells were seeded at a density of 10×10³ cells/mlin 1 ml of culture medium in 24 well plates and incubated 48-96 h beforebeing used in the assays. Medium was refreshed 24 h before each study.

5. Reactivity with Plastic-Immobilized Phospholipids

Phospholipids were dissolved in n-hexane to a concentration of 50 μg/ml.100 μl of this solution was added to wells of 96-well microtiter plates.After evaporation of the solvent in air, the plates were blocked for 2 hwith 10% fetal bovine serum diluted in DPBS containing 2 mM Ca²⁺(binding buffer).

9D2 antibody or annexin V were diluted in the binding buffer in thepresence of 10% serum at an initial concentration of 6.7 nM. Serialtwo-fold dilutions were prepared in the plates (100 μl per well). Theplates were then incubated for 2 h at room temperature. The plates werewashed and the 9D2 and annexin V were detected by goat anti-rat IgMconjugated to HRP and rabbit anti-human annexin V followed by goatanti-rabbit IgG conjugated to HRP (all diluted 1:1000), respectively.Secondary reagents were detected by using chromogenic substrate OPDfollowed by reading plates at 490 nm using a microplate reader(Molecular Devices, Palo Alto, Calif.).

The specificity of the 9D2 antibody binding was validated by usingcontrol rat IgM of irrelevant specificity (Pharmingen, San Diego,Calif.). The specificity of annexin V binding to phospholipids, which isCa²⁺-dependent, was determined by diluting the reagent in the DPBScontaining 5 mM EDTA. Additional negative controls consisted of washingthe plates with the binding buffer containing 0.2% of a detergent Tween20. This treatment extracts lipids, thus removing the phospholipid thatwas absorbed to plastic. Neither 9D2 antibody nor annexin V bound todetergent-washed plates.

6. Detection of Anionic Phospholipids on the Surface of CulturedEndothelial Cells

Endothelial cells were grown until they reached approximately 70%confluence. To induce PS exposure, cells were treated with H₂O₂ (200 μM)for 1 h at 37° C. Control and treated slides were washed with DPBScontaining Ca²⁺ and Mg²⁺ and fixed with 0.25% of glutaraldehyde dilutedin the same buffer. Excess aldehyde groups were quenched by incubationwith 50 mM of NH₄Cl for 5 min. To examine the effect of detergents andorganic solvents on detection of phospholipids, some slides werepre-incubated with acetone (5 min) or with PBS containing 1% (v/v)Triton™ X-100.

Cells were washed with DPBS (containing Ca²⁺, Mg²⁺ and 0.2% (w/v)gelatin) and incubated with 1 μg/ml of biotinylated annexin V(Pharmingen, San Diego, Calif.) or with 1 μg/ml of 9D2 antibody. After 2h of incubation, cells were washed with 0.2% gelatin buffer and wereincubated with streptavidin-HRP (1:500 dilution). Rat IgM of irrelevantspecificity and streptavidin alone were used as negative controls inthese studies. All steps were performed at room temperature. HRPactivity was measured by adding O-phenylenediamine (0.5 mg/ml) andhydrogen peroxide (0.03% w/v) in citrate-phosphate buffer, pH 5.5. After15 min, 100 μl of supernatant were transferred to 96 well plates, 100 μlof 0.18 M H₂SO₄ were added and the absorbance was measured at 490 nm.Alternatively, PS-positive cells were detected by addition of carbazolesubstrate, resulting in insoluble red-brownish precipitate. Each studywas performed in duplicate and repeated at least twice.

7. Inhibition of 9D2 and Annexin V Binding to Phospholipids by Liposomes

The specificity of phospholipid recognition was further confirmed bycompetition assays with various liposomes. Liposomes were prepared fromsolutions of 5 mg of a single phospholipid in chloroform. The solutionswere dried under nitrogen to form a thin layer in a round-bottomed glassflask. Ten ml of Tris buffer (0.1 M, pH 7.4) were then added and theflask was sonicated five times for 2 min. 9D2 or annexin V (6.66 nM)were pre-incubated with 200 μg/ml of liposomal solution for 1 h at roomtemperature. The mixture was added to phospholipid-coated plates orendothelial cell monolayers. The ability of 9D2 to bind to animmobilized phospholipid or cell surface in the presence or absence ofthe different liposomes was determined as described above.

8. Competition of 9D2 and Annexin V for Binding to Immobilized PS

Biotinylated 9D2 antibody and annexin V were prepared by incubatingpurified proteins with a 10-fold molar excess of N-hydroxysuccinimidebiotin (Sigma, Mo.) for 1 h at room temperature. Free biotin was removedby dialysis against PBS. The biotinylation procedure did not impair thePS-binding capacity of either protein. For competition studies,unmodified and biotinylated proteins were premixed with a 10-fold molarexcess of unmodified proteins. The mixtures were then added to PS-coatedplates. Bound reagents were detected by streptavidin-HRP conjugatediluted 1:1000. The binding to PS of each reagent in the absence of acompetitor was taken as the 100% value.

9. Growth of Subcutaneously Implanted Tumors

For localization studies, 2×10⁷ L540 human Hodgkin's lymphoma cells or1×10⁷ cells of other tumor types were injected subcutaneously into theright flank of SCID mice (Charles River. Wilmington, Mass.). Tumors wereallowed to reach a volume of 0.4-0.7 cm³. A minimum of three animals pergroup was used. Studies were replicated at least three times.

10. Orthotopic Model of Human MDA-MB-231 Breast Carcinoma

Female nu/nu or SCID mice were purchased from Charles River. MDA-MB-231human mammary carcinoma cells were implanted into the mammary fat padaccording to a published protocol (Price. 1996). Briefly, mice wereanesthetized and a 5-mm incision was made in the skin over the lateralthorax. The mammary pad was exposed to ensure the correct site forinjection of 1×10⁷ MDA-MB-231 cells re-suspended in 0.1 ml of saline.

11. Detection of Anionic Phospholipids in Tumor Bearing Mice In Vivo

Immunohistochemical techniques, in which 9D2 or annexin V are applieddirectly to sections of frozen tissues, do not discriminate betweenanionic phospholipids on the inner leaflet and the outer leaflet of theplasma membrane. To detect externally-positioned phospholipids, methodswere performed essentially as previously described (Example V; Ran etal., 1998). Tumor-bearing SCID mice were injected intravenously witheither 50 μg of 9D2 or biotinylated 9D2 antibody or 100 μg ofbiotinylated annexin V. Sixty min later mice were sacrificed and theirblood circulation was exsanguinated and perfused with heparinized salineas previously described (Burrows et al., 1992). All major organs andtumor were harvested and snap-frozen for preparation of cryosections.

Sections were blocked with PBS containing 10% serum. To prevent loss ofphospholipids during slide processing, detergents and organic solventswere omitted from blocking and washing buffers. Rat IgM was detectedusing goat anti rat IgM (μ specific)-HRP conjugate followed bydevelopment with carbazole or DAB (Fries et al., 1993). Biotinylatedreagents were detected by streptavidin conjugated to HRP.

Tumor sections derived from mice injected with saline or rat IgM ofirrelevant specificity served as negative controls. Additional controlsconsisted of incubating the slides in 1% Triton solution or in acetonefor 10 min. These treatments extract phospholipids. No signal wasdetected under these conditions. The number of positive vessels per highpower field was determined at magnification of ×100. At least 10 fieldsper section were examined and the average percentage of positive vesselswas calculated. Staining of the sections by this method for the presenceof 9D2 or annexin V detects cells having externalized anionicphospholipids that were accessible for binding by the reagents in vivo.

12. Identification and Quantification f PS-Positive Tumor Vessels

Structures with localized 9D2 antibody or annexin V were identified asblood vessels by morphological appearance on DAB-stained sections and byco-incident staining with the pan-endothelial cell marker, MECA 32 onserial sections of frozen tissues. Quantification on DAB-stainedsections was done by counting vessels stained by MECA 32, 9D2 or annexinV in serial sections of a tumor. Six slides of each tumor type derivedfrom 6 mice injected with 9D2 antibody, control rat IgM or annexin Vwere examined. At least 10 random fields per section (0.317 mm²/field)were scored in blinded fashion by two independent observers. The meannumbers and standard errors of vessels stained by 9D2, annexin V or MECA32 were calculated. The mean number of 9D2 or annexin V-positive vesselsdetermined in each tumor type group was compared to the mean number ofMECA 32-positive vessels in the same tumor group. The percentage of 9D2or annexin V-positive vessels was calculated.

In further studies, mice bearing MDA-MB-231 tumors (0.3-0.7 cm³ involume) were injected intravenously with 50 μg of biotinylated 9D2,control IgM or annexin V (six mice per group). Biotinylated reagentswere first incubated with streptavidin-Cy3 conjugate, washed in PBS,then incubated with MECA 32 antibody followed by FITC-tagged anti-ratIgG secondary antibody. Single images, taken with appropriate filtersfor Cy3 (red) and FITC (green) fluorescence respectively, were capturedby digital camera and transferred to a computer. Images of 10 randomfields (0.317 mm²/field) demonstrating yellow color (a product of mergedgreen and red fluorescence) were superimposed with the aid of Metaviewsoftware. The same method was used to analyze tumors from mice injectedwith control rat IgM or saline. The percentage of vessels with localized9D2 or annexin V was calculated as follows: mean number of yellowvessels per field divided by mean number of green (total) vesselsmultiplied by 100.

B. Results

1. Phospholipid Specificity of 9D2 Antibody and Annexin V

The 9D2 antibody specifically recognized anionic phospholipids (PS, PA,CL, PI, PG) and had no significant reactivity with neutral phospholipids(PE, PC and SM) in ELISA (FIG. 2A; Table 8). The order of strength ofbinding of 9D2 to phospholipids in ELISA was PA>PS=CL>PG=PI. The bindingwas antigen-specific since no binding was observed with several controlrat IgM of irrelevant specificity. Binding of 9D2 to any of the anionicphospholipids adsorbed to ELISA plates was blocked by liposomes preparedfrom any of the anionic phospholipids, but not by liposomes preparedfrom any of the neutral phospholipids.

TABLE 8 Phospholipid Specificity of 9D2 and Annexin V Abundance andlocation Phospholipid in the plasma membrane EC₅₀ of binding (pM) NameType under normal conditions^(a) 9D2 Annexin V PS Anionic Major PL(15%), 12 100 amino-PL located on inner side PA Anionic PL Minor PL(less than 1%) 2 100 PG Anionic PL Minor PL (less than 1%) 100 250 PIAnionic PL Major PL (7%), mainly 100 50 located on the inner side CLAnionic PL Absent from the plasma 15 130 membrane PE Neutral Major PL(22%), mainly >8000 100 amino-PL located on inner side SM Neutral MajorPL (9%), located >8000 >8000 choline-PL on the outer side PC NeutralMajor PL (46%), located >8000 >8000 choline-PL on the outer side^(a)Percentage of total phospholipids, taken from Fridrikkson, et al.,1999. Percentages may vary for different cell types.

Annexin V also bound to anionic phospholipids, but its binding was lessspecific than that of 9D2 in that it also bound strongly to the neutralphospholipid, PE. The order of strength of binding of annexin V tophospholipids in ELISA was PI>PS=PE=PA=CL>PG (Table 8). These findingsfor annexin V are consistent with earlier data (Andree et al., 1990).

The binding of 9D2 was unaffected by the presence of 5 mM EDTA, showingit did not require Ca²⁺ for binding to anionic phospholipids. Incontrast, the binding of annexin V to anionic phospholipids wasabolished in the presence of 5 mM EDTA, as expected from its knowndependence on Ca²⁺ for binding to anionic phospholipids or PE(Schlaepfer et al., 1987; Blackwood and Ernst, 1990).

Neither 9D2 nor annexin V bound to ELISA plates that had been coatedwith phospholipids but then washed with 0.2% Tween in saline, confirmingthat their binding was to the absorbed phospholipids. 9D2 and annexin Vdid not bind detectably to heparin, heparan sulfate or to double orsingle stranded DNA.

2. 9D2 Antibody and Annexin V do not Cross-Block Each Other's Binding toPs

To examine whether 9D2 antibody and annexin V compete for binding to PS,cross-blocking studies were performed using biotinylated proteins onPS-coated plates. Binding of biotinylated 9D2 antibody and annexin V wasblocked by a 10-fold molar excess of unmodified 9D2 and annexin V,respectively (Table 9). However, unmodified annexin V did not affect theability of biotinylated 9D2 to bind to the PS plate. Likewise, additionof unmodified 9D2 antibody did not alter the ability of biotinylatedannexin V to bind to the PS plate (Table 9).

TABLE 9 9D2 and Annexin V Do Not Cross-Block Binding to PS BindingPS-binding protein Competitor^(a) (% Control)^(b) Biotinylated annexin VAnnexin V 8% Biotinylated 9D2 Annexin V 93%  Biotinylated annexin V 9D295%  Biotinylated 9D2 9D2 5% ^(a)Annexin V or 9D2 antibody werepre-mixed in 10-fold molar excess over the biotinylated reagents.Binding of biotinylated reagents to PS on microtiter plates was detectedby streptavidin-HRP. ^(b)Reactivity of biotinylated reagents in theabsence of a competitor was taken as 100%. The mean values of triplicatedeterminations are presented. SD was less than 10% of the mean value.

These results indicate that 9D2 antibody and annexin V do notcross-block each other binding to PS-coated plates, either because theyrecognize different epitopes on the PS molecule or differentconformations of PS adsorbed on plastic.

3. Binding to Externalized Anionic Phospholipids on Cell Surfaces

The binding of 9D2 antibody and annexin V to cell surfaces was examinedusing mouse bEnd.3 endothelioma cells or bovine ABAE cells. Neither 9D2nor annexin V bound to non-permeabilized monolayers of either cell typeunder quiescent conditions. This indicates that the majority of anionicphospholipids of the plasma membrane are normally sequestered to thecytosolic domain. In contrast, strong staining was observed when cellswere pre-incubated with TNFα and actinomycin D under conditions thatcaused apoptosis in 90-100% of the endothelial cells.

To confirm that 9D2 and annexin V were binding to phospholipids on cellsurfaces. H₂O₂-treated bEnd.3 cells were incubated with 9D2 antibody orannexin V in the presence or absence of various competing liposomes.Anionic phospholipids become exposed on non-apoptotic, viable bEnd.3cells when they are pre-treated with a sub-toxic concentration (100-200μM) of H₂O₂ (Ran et al., 2002).

The binding of 9D2 antibody to H₂O₂-treated bend.3 cells was inhibitedby liposomes containing anionic phospholipids but not by liposomescontaining neutral phospholipids (FIG. 3). The magnitude of inhibitionof 9D2 binding to cells varied in the order PA>PS>CL>PG>PI, in closeagreement with the results obtained using plastic-immobilizedphospholipids (FIG. 2A and FIG. 2B). Similarly, the binding of annexin Vto H₂O₂-treated cells was blocked by liposomes containing PS, PA, PE, CLand, to a lesser extent PI and PG. Liposomes containing SM or PC did notblock annexin V binding to cells, all in agreement with the resultsobtained using plastic-immobilized phospholipids.

These results confirm that 9D2 binds to anionic phospholipids in theH₂O₂-treated endothelial cells whereas annexin V binds to PE in additionof anionic phospholipids.

4. Detection of Externalized Anionic Phospholipids on Cells In Vivo

Direct immunohistochemical techniques, in which 9D2 or annexin V areapplied directly to sections of frozen tissues, do not discriminatebetween anionic phospholipids on the inner leaflet and the outer leafletof the plasma membrane. To detect externally-positioned phospholipids,9D2 and annexin V were injected intravenously into tumor-bearing miceand localization to tumor vessels was determined by indirectimmunohistochemistry.

Mice bearing various types of solid tumors were injected intravenouslywith 9D2 antibody or biotinylated annexin V, and one hour later, wereexsanguinated and the tumors and normal tissues were removed and frozensections were prepared. Frozen sections of tissues were cut and stainedwith HRP-labeled anti-rat IgM or with HRP-labeled streptavidin todetermine to which cells the 9D2 and annexin V had bound afterinjection. Blood vessels were identified morphologically, and from theirpositive staining by the pan-endothelial cell antibody, MECA 32, onserial sections.

5. Biodistribution of 9D2 Antibody and Annexin V in Tumor Bearing Mice

9D2 antibody and annexin V localized to tumor vessels in all of fivetumors included in this study (FIG. 4; Table 10). The tumors were: humanMDA-MB-231 breast tumor growing orthotopically in the mammary fat padsof SCID mice; human L540 Hodgkin's tumor growing subcutaneously; humanNCI-H358 NSCLC growing subcutaneously; mouse B16 melanoma growingsubcutaneously and mouse Meth A fibrosarcoma growing subcutaneously.

TABLE 10 Specific Localization of 9D2 and Annexin V to Tumor Vessels RatIgM Tissue 9D2 Antibody^(a) control Annexin V^(b) Tumors MDA-MB-231 40.6± 5.4 — 45.3 ± 5.6 L540cy 19.3 ± 3.3 — 16.7 ± 3.9 NCI-H358 15.6 ± 4.1 —ND B16 23.4 ± 4.5 — 21.3 ± 6.6 Meth A 25.7 ± 6.8 — ND Normal Adrenal — —— Brain — — — Heart — — — Kidney  —^(c)  —^(c) — Intestine — — — Liver —— — Lung — — — Pancreas — — — Spleen — — — Testis — — — ^(a)Localizationof 9D2 antibody and rat IgM control in tumor bearing mice was determinedby injecting the antibody (50 μg), perfusing the blood circulation ofthe mice with saline and detecting the antibody on sections of thetissues by using an anti-mouse IgM - peroxidase conjugate. The resultsare presented as the mean (±SE) percentage of PS-positive vessels ofMECA 32-stained vessels per field of 0.317 mm². Six samples of each typewere analyzed. The mean number of MECA 32-positive vessels per 0.317 mm²field was 23, 25, 21, 18 and 19 ± 10 vessels for MDA-MB-231, L540cy,H358, B16 and Meth A tumors, respectively ^(b)Localization of annexin Vwas determined by injecting biotinylated annexin V followed by detectionon frozen sections using streptavidin-peroxidase conjugate.^(c)Non-antigen specific tubular staining was visible in both 9D2 andcontrol antibody recipients.

9D2 and annexin V gave essentially the same patterns of staining.Localization of the 9D2 antibody to tumor vessels was specific since nostaining of tumor endothelium was observed with rat IgM of irrelevantspecificity. Presumably, leakage of the control rat IgM out of tumorvessels occurred to some extent, but the staining of extravascular IgMwas too diffuse or too weak to discern by indirect immunohistochemistry.

No vascular localization of 9D2 antibody or annexin V was observed innine of the ten normal organs that were examined (Table 10). In thekidney, staining of tubules was observed that appeared not to be antigenspecific. Tubules were stained in both 9D2 and control rat IgMrecipients, presumably because of secretion of IgM or its metabolitesthrough this organ. The ovaries, a site of physiological angiogenesis,were not examined.

The percentage of 9D2 and annexin V positive vessels ranged from 40% inMDA-MB-231 tumors to 15% in H358 tumors. Anionic phospholipid-positivevessels were present on the luminal surface of capillaries and vesselsin all regions of the tumors, but were particularly prevalent in andaround regions of necrosis. Most anionic phospholipid-positive vesselsdid not show morphological abnormalities that were apparent by lightmicroscopy. Occasional vessels, particularly those located in necroticareas, showed morphological signs of deterioration. 9D2 antibody andannexin V also localized to necrotic and apoptotic tumor cells, whereaslocalization of the control IgM was not detectable (FIG. 4).

These findings demonstrate that anionic phospholipids are present on theluminal surface of vascular endothelial cells in various tumors but notin normal tissues.

6. Double Staining Studies

Double staining studies were also performed in which mice bearingorthotopic MDA-MB-231 breast tumors were injected intravenously withbiotinylated 9D2 antibody, biotinylated control IgM or biotinylatedannexin V. One hour later, the mice were exsanguinated, and their tumorswere removed and frozen sections were cut. The tumor sections were thenstained with Cy3-conjugated streptavidin to detect the biotinylatedproteins and with FITC-conjugated MECA32 to detect vascular endothelium.This detection method labeled the biotinylated proteins and the vascularendothelium by red and green. Where the biotinylated proteins are boundto the endothelium, the converged image appears yellow.

In these studies, the biotinylated 9D2 and annexin V appeared mostly tobe bound to the vascular endothelium, because their staining patternsconverged with that of MECA 32. About 40% of MECA 32 positive vesselsbound 9D2 and annexin V, in close agreement with the results obtained byindirect immunohistochemistry. However, leakage of the biotinylatedproteins into the tumor interstitium was detected by double staining,whereas it was not apparent by indirect immunohistochemistry.

Biotinylated proteins were visible outside the vascular endotheliumaround a minority (about 5%) of vessels. In tumors from mice that hadbeen injected with biotinylated rat IgM of irrelevant specificity, thebiotinylated IgM had also leaked into the tumor interstitium around asimilar percentage (about 5%) of vessels, but mostly appeared not to bebound by the vascular endothelium. Presumably, the detection ofextravasated 9D2 and annexin V by the double staining technique, but notby the indirect immunohistochemistry technique, reflects the greatersensitivity of the former technique and the greater precision with whichtwo staining patterns can be compared. Non-injected control tumors werecompletely unstained by streptavidin-Cy3, indicating that redfluorescence corresponds to a localized protein.

Example VII Anionic Phospholipid Membrane Translocation in a TumorEnvironment

The discovery of aminophospholipids and anionic phospholipids as in vivosurface markers unique to tumor vascular endothelial cells prompted theinventors to further investigate the effect of a tumor microenvironmenton the translocation and outer membrane expression of such molecules.The present example shows that exposing endothelial cells in vitro tocertain conditions that mimic those in a tumor duplicates the earlierobserved aminophospholipid and anionic phospholipid surface expressionin intact, viable cells.

A. Materials and Methods

1. Iodination of Annexin V

Recombinant human annexin V was purified from E. coli transformed withET12a-Panionic phospholipid1 plasmid (obtained from Dr. J. Tait,University of Washington, Seattle). The purity of the protein and thebinding to PS were confirmed on SDS-PAGE and on PS-coated plastic,respectively. Rabbit polyclonal, affinity-purified anti-annexin Vantibodies were used to detect annexin V bound to PS. Annexin V wasradiolabeled with ¹²⁵I using Chloramine T as described by Bocci (1964).The specific activity was approximately 1×10⁶ cpm per μg of protein, asmeasured by a Bradford assay (1976).

2. Endothelial Cell Treatment

Endothelial cells were treated with cytokines or growth factors at theconcentrations listed in Table 11. All reagents were diluted in mediumcontaining 10% serum and incubated with the cells at 37° C. for 24 h.

To study the effect of hypoxia, cells were seeded on 24 well plates andwere incubated in a humidified normoxic atmosphere (21% O₂5% CO₂) for 48h before being transferred to a humidified hypoxic atmosphere (1% O₂, 5%CO₂, 94% N₂) in a sealed chamber (Billups Rothenberg Inc., Del Mar,Calif.). Cells were incubated in a hypoxic chamber for 24 h at 37° C.and were then returned to a normoxic environment for 4 h at 37° C. Thecells were compared to a parallel culture from an identical passage,seeded on the same day and maintained entirely under normoxicconditions. In some studies, IL-1α (10 ng/ml) and TNFα (20 ng/ml) wereadded to the medium before transfer to the hypoxic chamber.

To examine the effect of an acidic microenvironment, cells were exposedto the growth medium lacking bicarbonate, which was adjusted todifferent pHs (ranging between 7.3 and 6.2) with the required amount ofHCl. Cells were incubated at 37° C. in the absence of CO₂. It wasconfirmed that culture media held the assigned pH during the 24 h periodof culture. These experimental conditions were not toxic to eitherbovine or mouse endothelial cells and had no effect on cell morphologyor viability of the attached monolayer.

3. Detection of PS on Cultured Endothelial Cells by ¹²⁵I-Labeled AnnexinV

After treatment with the reagents described above, treated and controlcells were incubated with 7.1 pmoles of ¹²⁵I-labeled annexin V (200μl/well) in the binding buffer. After 2 h incubation at roomtemperature, cells were washed extensively and dissolved in 0.5 M ofNaOH. The entire volume of 0.5 ml was transferred to plastic tubes andcounted in a gamma counter. Non-specific binding was determined in thepresence of 5 mM EDTA and was subtracted from experimental values. Theresults were expressed as net pmoles of cell-bound annexin V, normalizedper 1×10⁶ cells.

Maximal binding of annexin V was determined on cells simultaneouslytreated with actinomycin D and TNFα (50 ng/ml of each component). As hasbeen previously reported, these agents cause apoptosis and PS exposurein 90-100% of endothelial cells (Lucas et al., 1998). Basal binding of¹²⁵I-annexin V to untreated cells was determined in the presence ofmedium with 10% serum. The amount of ¹²⁵I-annexin V that bound to theuntreated cultures was subtracted from that in the treated cultures.Exposure of PS was calculated according to the following formula:cell-bound annexin V (pmoles) under experimental conditions divided bymaximal annexin V binding (pmoles), multiplied by 100. Each study wasperformed in duplicate and was performed at least three times. Meanvalues were calculated. The SE of the mean values from three separateexperiments was less than 5%.

B. Results

1. Induction by H₂O₂

Mouse bEnd.3 endothelial cells were seeded at an initial density of50,000 cells/well. Twenty-fours later cells were incubated withincreasing concentrations of H₂O₂ (from 10 μM to 500 μM) for 1 hour at37° C. or left untreated. At the end of the incubation, cells werewashed 3 times with PBS containing 0.2% gelatin and fixed with 0.25%glutaraldehyde. Identical wells were either stained with anti-PS IgM ortrypsinized and evaluated for viability by the Trypan Blue exclusiontest. For the anti-PS staining, after blocking with 2% gelatin for 10min., cells were incubated with 2 μg/ml of anti-PS antibody, followed bydetection with anti-mouse IgM-HRP conjugate.

Exposing endothelial cells to H₂O₂ at high concentrations causes PStranslocation in ˜90% cells. However, this is accompanied by detachmentof the cells from the substrate and cell viability decreasing to about50-60%. The association of surface PS expression with decreasing cellviability is understandable, although it is still interesting to notethat ˜90% PS translocation is observed with only a 50-60% decrease incell viability.

Using lower concentrations of H₂O₂ resulted in significant PS expressionwithout any appreciable reduction in cell viability. For example, PS wasdetected at the cell surface of about 50% of cells in all H₂O₂ treatedwells using H₂O₂ at concentrations as low as 20 μM. It is important tonote that, under these low H₂O₂ concentrations, the cells remainedfirmly attached to the plastic and to each other, showed nomorphological changes and had no signs of cytotoxicity. Detailedanalyses revealed essentially 100% cell-cell contact, retention ofproper cell shape and an intact cytoskeleton.

The 50% PS surface expression induced by low levels of H₂O₂ was thusobserved in cell populations in which cell viability was identical tothe control, untreated cells (i.e., 95%). The PS expression associatedwith high H₂O₂ concentrations was accompanied by cell damage, and thePS-positive cells exposed to high H₂O₂ concentrations were detached,floating and had disrupted cytoskeletons.

The maintenance of cell viability in the presence of low concentrationsH₂O₂ is consistent with data from other laboratories. For example,Schorer et al. (1985) showed that human umbilical vein endothelial cells(HUVEC) treated with 15 μM H₂O₂ averaged 90 to 95% viability (reportedas 5% to 10% injury), whilst those exposed to 1500 μM H₂O₂ were only0%-50% viable (50% to 100% injured).

The use of H₂O₂ to mimic the tumor environment in vitro is alsoappropriate in that the tumor environment is rich in inflammatory cells,such as macrophages, PMNs and granulocytes, which produce H₂O₂ and otherreactive oxygen species. Although never before connected with stabletumor vascular markers, inflammatory cells are known to mediateendothelial cell injury by mechanisms involving reactive oxygen speciesthat require the presence of H₂O₂ (Weiss et al., 1981; Yamada et al.,1981; Schorer et al., 1985). In fact, studies have shown thatstimulation of PMNs in vitro produces concentrations of H₂O₂ sufficientto cause sublethal endothelial cell injury without causing cell death(measured by chromium release assays) or cellular detachment; and thatthese H₂O₂ concentrations are attainable locally in vivo (Schorer etal., 1985).

The present in vitro translocation data correlates with the earlierresults showing that anti-PS antibodies localize specifically to tumorvascular endothelial cells in vivo, and do not bind to cells in normaltissues. The finding that in vivo-like concentrations of H₂O₂ induce PStranslocation to the endothelial cell surface without disrupting cellintegrity has important implications in addition to validating theoriginal in vivo data and the inventors' therapeutic approaches.

Human, bovine and murine endothelial cells are all known to bePS-negative under normal conditions. Any previously documented PSexpression has always been associated with cell damage and/or celldeath. This is not the case in the present studies, where normalviability is maintained. This shows that PS translocation in tumorvascular endothelium is mediated by biochemical mechanisms unconnectedto cell damage. This is believed to be the first demonstration of PSsurface expression in morphologically intact endothelial cells and thefirst indication that PS expression can be disconnected from theapoptosis pathway(s). Returning to the operability of the presentinvention, these observations again confirm that PS is a sustainable,rather than transient, marker of tumor blood vessels and a suitablecandidate for therapeutic intervention.

2. Induction by Thrombin

Thrombin was also observed to increase PS expression, although not tothe same extent as H₂O₂. This data is also an integral part of thetumor-induction model of PS expression developed by the presentinventors: thrombin-induced PS surface expression in normal tissueswould also further coagulation as PS expression coordinates the assemblyof coagulation initiation complexes.

The tumor environment is known to be prothrombotic, such that tumorvasculature is predisposed to coagulation (U.S. Pat. No. 5,877,289). Asthrombin is a product of the coagulation cascade, it is present in tumorvasculature. In fact, the presence of thrombin induces VCAM expression,contributing to the inventors' ability to exploit VCAM as a targetablemarker of tumor vasculature (U.S. Pat. Nos. 5,855,866; 5,877,289). Thepresent data showing that thrombin also induces PS expression is thusboth relevant to targeting aminophospholipids with naked antibodies andtherapeutic conjugates, and further explains the beneficial effects ofthe anti-VCAM coaguligand containing Tissue Factor (Example I).

3. Other Agents of Oxidative Stress

Mouse bEnd.3 or bovine ABAE cells in vitro were treated for 24 h withvarious concentrations of factors and conditions that are present in themicroenvironment of many tumors (Lichtenbeld et al., 1996; Harris etal., 1996), such as hypoxia/reoxygenation, thrombin, acidity,inflammatory cytokines and hydrogen peroxide (Table 11).

Externalization of PS and anionic phospholipids was quantified bymeasuring ¹²⁵I-annexin V binding. The amount of annexin V binding wascompared with that of cells in which apoptosis of 90-100% of cells hadbeen induced by combined treatment with actinomycin D and TNF-α.Actinomycin D and TNF-α induced the binding of 6.2 pmoles of annexin Vper 10⁶ cells (3.8×10⁶ molecules of annexin V per cell) on both celltypes, in good agreement with literature reports (Rao et al., 1992).This value was taken as the maximal level of externalized anionicphospholipids.

TABLE 11 Induction of PS by Recreating Tumor Environment ¹²⁵I-Annexin V(% of Max binding) Treatment Concentration ABAE CELLS bEnd.3 cellsMedium with N/A 0 0 10% serum Actinomycin 50 ng/ml each 100 100 D + TNFα VEGF 20 ng/ml 0 0 FGF-2 20 ng/ml 0 0 Scatter factor 40 ng/ml 0 0 TGFβ₁ 20 ng/ml 0 0 PDGF-BB 20 ng/ml 0 0 IL-10 20 ng/ml 0 0 IL-8 20 ng/ml 00 IL-6 20 ng/ml 0 0 IL-1α 10 ng/ml 6.4 7.5 IL-1β 10 ng/ml 5.8 5.5Interferon 40 ng/ml 8.6 2.8 TNFα 20 ng/ml 7.4 13.7 Thrombin 50 nM 8.817.4 Hypoxia 1% O₂ 15.0 to 17.5 22.5 Hypoxia + IL-1α Same as above 26.031.0 Hypoxia + TNFα Same as above 33.0 36.0 pH 6.6 N/A 20.2 18.9Hydrogen 200 μM 95.5 98.4 peroxide

In Table 11, the concentrations of cytokines, growth factors andthrombin used were selected from literature values to have maximalstimulatory effect on cultured endothelial cells. These concentrationsdid not cause toxicity over the period of the test (24 h) as judged bymorphological appearance, a lack of detachment, and a lack of uptake oftrypan blue. The concentration of H₂O₂ employed was the maximalconcentration that did not cause cytotoxicity under the chosenconditions.

The basal binding of ¹²⁵I-annexin V was determined in the presence ofgrowth medium alone. Maximal PS exposure was determined after inductionof apoptosis by the combined treatment with actinomycin D and TNF α.Average of duplicates from three separate studies is presented. Standarderror was less than 5%.

Untreated cells were largely devoid of externalized PS, as judged byannexin V or anti-PS (9D2) antibody binding (Table 11). The basalbinding in the presence of growth medium alone was 0.44 and 0.68 pmolesof ¹²⁵I-annexin V for ABAE and bEnd.3 cells, respectively. Thiscorresponds to approximately 7.1% and 10.9% of the maximal binding forABAE and bEnd.3 cells, respectively, which correlated well with thefinding that approximately 10% of cells bound biotinylated annexin Vunder the same conditions.

VEGF, HGF, FGF, TGFβ₁, PDGF, IL-6, IL-8 and IL-10 did not increasebinding of ¹²⁵I-annexin V above the basal level for untreated cells.Inflammatory mediators (IL-1α, IL-1β. TNFα and interferon) caused asmall but reproducible increase in PS and anionic phospholipidtranslocation that ranged from 5 to 8% of the maximal level for ABAEcells and from 3 to 14% for bEnd3 cells.

Hypoxia/reoxygenation, thrombin or acidic external conditions (pH6.8-6.6) induced a moderately high externalization of PS and anionicphospholipid that ranged from 8 to 20% of the maximal level for ABAEcells and from 17 to 22% of the maximal level for bend.3 cells. Thelargest increase in PS and anionic phospholipid translocation wasobserved after treatment with 100 to 200 μM of hydrogen peroxide. Thistreatment caused nearly complete (95%) externalization of PS in bothcell types as judged by ¹²⁵I-annexin V binding (Table 11). More than 70%of ABAE and bEnd.3 cells bound biotinylated annexin V, as judgedimmunohistochemically.

Endothelial cells in which PS and anionic phospholipid translocation wasgenerated by treatment with hypoxia/reoxygenation, thrombin, acidity,TNFα, IL-1 or H₂O₂ remained attached to the matrix during time period ofthe assay (24 h), retained cell-cell contact and retained their abilityto exclude trypan blue dye. Normal PS and anionic phospholipidorientation was restored 24 to 48 h later in the majority of the cellsafter the inducing-factor was removed, or the culture conditions werereturned to normal. These results indicate that mild oxidative stress,created by direct application of H₂O₂ or indirectly byhypoxia/reoxygenation, acidity, thrombin, or inflammatory cytokines,triggers a transient translocation of PS and anionic phospholipids onviable endothelial cells.

4. Combined Effects of Inflammatory Cytokines and Hypoxia/Reoxygenation

Enhanced PS and anionic phospholipid exposure was observed when ABAE andbEnd.3 cells were subjected to hypoxia/re-oxygenation in the presence ofIL-1α or TNFα. In the absence of the cytokines, hypoxia/reoxygenationincreased PS-exposure by ABAE cells to 15%-17.5% of the maximum levelfor cells treated with apoptotic concentrations of actinomycin D andTNFα. In the presence of sub-toxic concentrations of IL-1α or TNFα,hypoxia/reoxygenation increased anionic phospholipid-exposure to 26% and33% respectively of the maximum (FIG. 5; Table 11). Comparison with theeffect of cytokines in the absence of hypoxia/reoxygenation indicatesthat the combination of cytokines and hypoxia/reoxygenation had agreater than additive effects on PS-exposure. Similar effects wereobserved on bEnd.3 cells.

Therefore, in the tumor environment, the exposure of PS and anionicphospholipids induced by hypoxia/re-oxygenation may be amplified byinflammatory cytokines and possibly by such other stimuli as acidity andthrombin.

These in vitro studies shed light on the mechanism of PS exposure ontumor endothelial cells in vivo. They show that various factors inducePS exposure on endothelial cells without causing cytotoxicity, whichmimics the situation in tumors in vivo. Hypoxia followed byreoxygenation, acidity, and thrombin most increased PS exposure onviable endothelial cells. Inflammatory cytokines (TNFα and IL-1α) alsocaused a weak but definite induction of PS exposure.

These conditions are likely to be the major inducing stimuli in tumorsin vivo because: i) PS positive endothelium is prevalent in and aroundregions of necrosis where hypoxia, acidity, thrombosed blood vessels,and infiltrating host leukocytes are commonly observed; ii) the findingthat hypoxia/reoxygenation amplifies the weak PS-exposing activity ofTNFα and IL-1 on endothelial cells in vitro correlates with thesituation in vivo in tumors where hypoxia and cytokine-secreting tumorand host cells co-exist; iii) hypoxia/reoxygenation and thrombin havebeen reported to generate reactive oxygen species (ROS) in endothelialcells through activation of NADPH oxidase-like membrane enzyme (Zuluetaet al., 1995). ROS produced by malignant cells might contribute toendothelial cell injury (Shaughnessy et al. 1989). Hydrogen peroxide wasthe most powerful inducer of PS exposure on cultured endothelial cellsfound in the present study, providing indirect support for theinvolvement of ROS.

Externalized PS provides a negative phospholipid surface upon whichcoagulation factors concentrate and assemble. This may contribute to theprocoagulant status on the tumor endothelium that has long beenrecognized. PS also provides an attachment site for circulatingmacrophages (McEvoy et al., 1986), T lymphocytes (Qu et al., 1996) andpolymorphonuclear cells that assist in leukocyte infiltration intotumors. Adherence of activated macrophages, polymorphonuclear cells andplatelets to PS on tumor endothelium may lead to further secretion ofreactive oxygen species and further amplification of PS exposure.

Example VIII Anti-Tumor Effects of Annexin Conjugates

The surprising finding that aminophospholipids and anionic phospholipidsare stable markers of tumor vasculature means that antibody-therapeuticagent constructs can be used in cancer treatment. In addition to usingantibodies as targeting agents, annexins, and other specific bindingproteins, can also be used to specifically deliver therapeutic agents totumor vasculature. The following data shows the anti-tumor effects thatresult from the in vivo administration of annexin-TF constructs.

A. Methods

An annexin V-tTF conjugate was prepared and administered to nu/nu micewith solid tumors. The tumors were formed from human HT29 colorectalcarcinoma cells that formed tumors of at least about 1.2 cm³. Theannexin V-tTF coaguligand (10 μg) was administered intravenously andallowed to circulate for 24 hours. Saline-treated mice were separatelymaintained as control animals. After the one day treatment period, themice were sacrificed and exsanguinated and the tumors and major organswere harvested for analysis.

B. Results

The annexin V-tTF conjugate was found to induce specific tumor bloodvessel coagulation in HT29 tumor bearing mice. Approximately 55% of thetumor blood vessels in the annexin V-tTF conjugate treated animals werethrombosed following a single injection. In contrast, there was minimalevidence of thrombosis in the tumor vasculature of the control animals.

Example IX Anti-Tumor Effects of 3SB Anti-PS Antibodies

The present example shows the anti-tumor effects of anti-PS antibodiesusing syngeneic and xenogeneic tumor models. The 3SB antibody used inthis study binds to PS (and PA), but is essentially devoid of reactivitywith PE. This anti-PS antibody caused tumor vascular injury, accompaniedby thrombosis, and tumor necrosis.

The effects of anti-PS antibodies were first examined in syngeneic andxenogeneic tumor models using the 3SB antibody. For the syngeneic model,1×10⁷ cells of murine colorectal carcinoma Colo 26 (obtained from Dr.Ian Hart, ICRF, London) were injected subcutaneously into the rightflank of BALB/c mice. In the xenogeneic model, a human Hodgkin'slymphoma L540 xenograft was established by injecting 1×10⁷ cellssubcutaneously into the right flank of male CB 17 SCID mice. Tumors wereallowed to grow to a size of about 0.6-0.9 cm³ before treatment.

Tumor-bearing mice (4 animals per group) were injected i.p. with 20 μgof 3SB anti-PS antibody (IgM), control mouse IgM or saline. Treatmentwas repeated 3 times with a 48 hour interval. Animals were monitoreddaily for tumor measurements and body weight. Tumor volume wascalculated as described in Example I. Mice were sacrificed when tumorshad reached 2 cm³, or earlier if tumors showed signs of necrosis orulceration.

The growth of both syngeneic and xenogeneic tumors was effectivelyinhibited by treatment with 3SB anti-PS antibodies (FIG. 6A and FIG.6B). Anti-PS antibodies caused tumor vascular injury, accompanied bythrombosis, and tumor necrosis. The presence of clots and disintegrationof tumor mass surrounding blocked blood vessels was evident.

Quantitatively, the 3SB anti-PS antibody treatment inhibited tumorgrowth by up to 60% of control tumor volume in mice bearing large Colo26 (FIG. 6A) and L540 (FIG. 6B) tumors. No retardation of tumor growthwas found in mice treated with saline or control IgM. No toxicity wasobserved in mice treated with anti-PS antibodies, with normal organspreserving unaltered morphology, indistinguishable from untreated orsaline-treated mice.

Tumor regression started 24 hours after the first treatment and tumorscontinue to decline in size for the next 6 days. This was observed inboth syngeneic and immunocompromised +tumor models, indicating that theeffect was mediated by immune status-independent mechanism(s). Moreover,the decline in tumor burden was associated with the increase ofalertness and generally healthy appearance of the animals, compared tocontrol mice bearing tumors larger than 1500 mm³. Tumor re-growthoccurred 7-8 days after the first treatment.

The results obtained with anti-PS treatment of L540 tumors are furthercompelling for the following reasons. Notably, the tumor necrosisobserved in L540 tumor treatment occurred despite the fact that thepercentage of vessels that stained positive for PS in L540 tumors wasless than in HT 29 and NCI-H358 tumors. This implies that even morerapid necrosis would likely result when treating other tumor types.Furthermore, L540 tumors are generally chosen as an experimental modelbecause they provide clean histological sections and they are, in fact,known to be resistant to necrosis.

Example X Anti-Tumor Effects of Antibody (9D2) Against AnionicPhospholipids

This example demonstrates the effects of the 9D2 antibody, which bindsto PS and other anionic phospholipids, in anti-tumor studies in vivo.

A high dose (>150 μg) of the rat antibody that binds to anionicphospholipids, 9D2, was injected into nude mice bearing H358 tumors.Immunolocalization studies shows that it strongly localized to tumorendothelium (4+), although some low level, non-specific binding of 9D2by normal vessels was observed due to the high dose (as would beobserved for a control IgM antibody of irrelevant specificity).

When 9D2 was injected i.p. into a SCID mouse with an L540 tumor forascites production, the tumor became necrotic and collapsed. Uponinjection of a control antibody (MK 2.7, rat IgG) into a SCID mouse withan L540 tumor, no similar effects were observed.

The effect of the 9D2 anti-PS antibody on the growth of L540 tumors invivo was then determined more precisely. Treatment was started whentumors reached 200-250 μl (day 0). From day 0 to day 7, mice wereinjected i.p. with ˜150 μg of IgM (200 μl supernatant) or 200 μl of 10%DMEM. From day 7 to day 22, mice were injected i.p. with ˜300 μg of IgM(400 μl supernatant) or 400 μl of 10% DMEM. Day 22 was the last day oftreatment and the mice were sacrificed.

As shown in Table 12, from days 10 to 22, tumor growth is generallyinhibited by about 40% to 50%. At the end of the study, only 4 mice inthe treated group have tumors larger than 2000 μl in volume, in contrastto 9/9 in the control group.

TABLE 12 Effects of Anti-PS Antibodies on L540 Tumors In Vivo Day afterAverage Tumor Number of mice with start of the Volume (μl) % tumorvolume > 2000 μl treatment Control Treated Inhibition Control Treated 0341 320 6.2 0 0 1 464 325 10.8 0 0 3 412 415 0 0 0 7 687 455 33.8 0 0 10904 544 39.9 1/9 0 13 945 545 42.4 1/9 0 15 1373 685 50.1 4/9 1/10 171426 842 41.0 4/9 4/10 20 1992 987 50.5 6/9 4/10 22 2560 1365 53.3 9/94/10

In another in vivo study, the effects of the rat anti-PS antibody on thegrowth of L540 tumors in CB17 SCID mice were followed for 45 days aftertumor cell injections. These tumor-bearing mice were treated with 300 μgof anti-PS antibody daily, i.p. or with 300 μl of 10% DMEM daily, i.p.,as a control. Various parameters of tumor treatment were markedly betterin the treated group in comparison to those of the controls (Table 13).

TABLE 13 Effects of Anti-PS Antibodies on L540 Tumors In Vivo Otherparameters Control Treated % Regressed tumors¹ 0 40% (60 days posttreatment) % Regressed tumors¹ 0 20% (90 days post treatment) Averagevolume of 537 ± 30 366 ± 56 secondary tumors (μl)² ¹Tumors too small tomeasure in treated mice at indicated times (60 vs. 90 days) aftertreatment ²Metastases in lymph nodes

In a further study, the 9D2 antibody was injected intraperitoneally at adose of 100 μg 3 times per week to mice with L540 tumors. The tumor sizewas measured with calipers twice a week. The anti-tumor effects incomparison to the control group is shown in FIG. 7. The numbers inparenthesis indicate the number of mice with regressed tumors per totalnumber of mice per group.

Example XI Anti-Tumor Effects of Anti-PS Antibody 3G4

The present example demonstrates additional anti-tumor effects using theanti-PS antibody 3G4 in syngeneic and xenogeneic tumor models. The 3G4antibody used in this study is an IgG antibody that binds to PS andother anionic phospholipids (Example IV).

A. Protocols for Animal Tumor Studies

The effects of 3G4 was examined in syngeneic and xenogeneic tumormodels. The general protocol for the animal tumor treatment studies isconducted as follows. Unless particular differences are specified, thisis the protocol used throughout the studies of the present application.

The animals are obtained from Charles Rivers laboratories. The mice are4-5 weeks, female, C.B-17 SCID or Fox Chase SCID mice. Mice are housedin autoclaved caging, sterile food and water, with sterile handling. Allprocedures performed in laminar flow hoods. Mice are acclimated 1 weekand then ear-tagged and a blood sample (approximately 75-100 μl) takenfrom the tail vein to check for leakiness by ELISA. Any mice that failthe leakiness ELISA test should not be used for test procedures. Miceare injected orthotopically with tumor cells into mammary fat pad (MFP)or subcutaneously into the right flank 2-3 days post ear-tagging andblood sample removal.

In the orthotopic model, 1×10⁷ cells in 0.1 ml DMEM are typicallyinjected into MFP of anesthetized mice. Mice are anesthetized with 0.075ml of mouse cocktail injected IP. The mouse cocktail is 5 ml Ketamine(100 mg/ml); 2.5 ml Xylazine (20 mg/ml); 1 ml Acepromazine (10 mg/ml);11 ml sterile water. Dosage is 0.1 ml per 20-30 grams body weight viathe IP route for a duration of 30 minutes.

Once the mouse is anesthetized, as measured by no response to toe/footpinch, the mouse is laid on its left side and wiped with 70% ethanoljust behind the head and around the right forearm/back area. A 2-3 mmincision is made just behind the right forearm (lateral thorax), whichreveals a whitish fat pad when the skin flap is raised. 0.1 ml of cellsare injected into the fat pad using a 1 ml syringe and a 27-gaugeneedle, producing a bleb in the fat pad. The incision is closed using a9 mm sterile wound clip. The mouse is returned to its cage and observeduntil it has wakened from anesthesia and is mobile. Post-operativehealth status is determined, and if any signs of distress are observed,the animal is given acetaminophen (0.24 mg/ml)+codeine (0.024 mg/ml) inthe drinking water. The wound clip is removed after 1 week. This methodis used so that the cells are accurately placed into the selected siteand not into the subcutaneous region. Tumors will be approximately 200μl in volume (L×W×W) in 14-15 days and the take rate is essentially100%.

In the subcutaneous model, mice are typically injected with 1×10⁷ cellsin 0.2 ml. Mice are not anesthetized, but are restrained using a steadygrip of mouse skin exposing the right flank. A 1 ml syringe with a 23gauge needle is used to inject 1×10⁷ cells in 200 μl, just under theskin of the mice and a bleb will be seen. It is not unusual to observe asmall amount of fluid leak from the injection site. A twisting motionmay be used when withdrawing the needle from the subcutaneous injectionto reduce this leakage. Tumor volume is measured by L×W×H.

In the perfusion protocol, mice are injected IV with 1000 U of heparinin 0.2 ml saline. Mice are then be sedated by injecting the mouse IPwith 0.1 ml mouse cocktail. Once the mouse is sedated enough, asmeasured by no reflex when toe/foot is pinched, the thoracic cavity isopened to expose the heart and lungs. A 30 gauge needle attached totubing and perfusion pump is inserted into the left ventricle. The rightventricle is snipped so that blood can drip out. Saline is pumpedthrough for 12 minutes at a speed of 1 ml per minute. At the end of theperfusion, the needle and tubing are removed. Tissues are removed forfurther studies, either immunohistochemistry or pathology.

B. Tumor Treatment Results

For the syngeneic model, Meth A mouse fibrosarcoma tumor cells wereused. In one xenogeneic model, human MDA-MB-231 breast tumor cells wereseeded into the mammary fat pad. In another xenogeneic model, a largehuman Hodgkin's lymphoma L540 xenograft was established by injectingcells and allowing the tumor to grow to a size of over 500 mm³ beforetreatment. Tumor-bearing mice (10 animals per group) were injected i.p.with 100 μg of 3G4 anti-PS antibody (IgG) as opposed to control.Treatment was repeated 3 times a week. Animals were monitored twice aweek for tumor measurements.

The growth of both syngeneic and xenogeneic tumors was effectivelyinhibited by treatment with 3G4 anti-PS antibodies. Treatment for thefirst 20 to 30 days is shown in FIG. 8A, FIG. 8B and FIG. 8C. Theantibodies caused tumor vascular injury, localized thrombosis and tumornecrosis.

The treatment of the syngeneic, Meth A tumor cells was particularlysuccessful, and the treatment of the human MDA-MB-231 breast tumor cellsgrowing in the mammary fat pad also produced tumor regressions (FIG. 8Aand FIG. 8B). Even in mice bearing large L540 tumors, known to beresistant to necrosis, the 3G4 antibody treatment inhibited tumor growthin comparison to control. No retardation of tumor growth was found incontrol mice. No toxicity was observed in mice treated with anti-PSantibodies.

Tumors were also established using MD-MBA-435s cells and treated asdescribed above. The growth of these tumors was also effectivelyinhibited by treatment with the 3G4 antibody. The treatment of largeL540 tumors, MDA-MB-231 and MD-MBA-435s tumor cells for 60 days is shownin FIG. 8D, FIG. 8E and FIG. 8F. The antibodies caused tumor vascularinjury, thrombosis and necrosis and retarded tumor growth, with noevidence of toxicity.

MD-MBA-435s lucerifase cells were obtained from Dr. Angels SierraJimenez, Barcelona, Spain and were grown in 10% DMEM. Mice were injectedwith tumor cells as described as above, and at 2 weeks post injection,the tumors were measured and the volume recorded. Treatment of mice withtumors of similar average volumes (200 mm³) was performed using the 3G4antibody and the chimeric 3G4 antibody, produced as described in ExampleXIX, versus control. Treatment was initiated by IP injection (800 μg) atday 15 and continued with injections of 200 μg every two to three daysuntil the final injection of 400 μg at day 35. Tumor volumes and mousebody weights were measured on injection days. Mice were sacrificed andperfused with saline for 12 minutes. The organs and tumor were removed,snap-frozen in liquid nitrogen and the tumor sectioned forimmunohistochemistical analysis.

This study showed that both the 3G4 antibody and the chimeric 3G4antibody effectively retarded tumor growth as opposed to control (FIG.8G).

Example XII Anti-Viral Effects of Anti-PS Antibodies Against CMV

Surprisingly switching fields from tumor vasculature to viralinfections, the inventors next reasoned that antibodies toaminophospholipids and anionic phospholipids would also likely exert ananti-viral effect. The present example indeed shows this to be true,first using the 3G4 antibody in the treatment of cytomegalovirus (CMV)infection.

A. Methods

1. Treatment of CMV-Infected Cells In Vitro

Confluent monolayers of human diploid foreskin fibroblasts (HHF-R2) in6-well plates were infected with human CMV AD169 expressing greenfluorescent protein (GFP) at an MOI=0.01 as previously described(Bresnahan et al., 1996). Briefly, the cells were incubated with virusin a total volume of 1 ml per well at 37° C. for 90 minutes. During theinfection, the plates were gently rocked every 30 minutes. Following theinfection, the cell supernatant was removed and DMEM/10% FBS/pen-strep(2 ml per well) was added to each well.

Dilutions of 3G4 or the isotype matched control antibody GV39G (100μg/ml and 50 μg/ml) were added to the wells. The infected cells wereincubated at 37° C. for a total of 19 days. The medium and antibody ineach well was replaced every 3 days. On day 19, the cells andsupernatants from each well were harvested and frozen at −80° C. untilthe plaque assays were carried out.

2. Fluorescent Microscopy

The recombinant CMV expresses GFP under the control of the SV40promoter. Hence, infected cells appear green under a fluorescentmicroscope. In these studies, the antibody treated CMV-infected cellswere observed under a fluorescent microscope at days 2, 3 and 9.

3. Plaque Assays

The plaque assays were carried out using standard protocols. Briefly,the frozen cells cell suspensions were thawed quickly at 37° C. andcentrifuged to remove debris at 1000 rpm for 1 minute. Differentdilutions of the cell supernatants were added to sub-confluentmonolayers of HHF-R2 cells in 6-well plates and the cells incubated at37° C. for 90 minutes (the plates were gently rocked every 30 minutes).Following the infection, the cell supernatants were removed and replacedwith 2 ml of DMEM/10% FBS. On day 4, the supernatant in each well wasremoved and the cells overlayed with 0.01% low melting pointagarose/DMEM/10% FBS. The plates were incubated at 37° C. for a total of14 days post-infection. On day 14, the infected monolayers were fixedwith 10% buffered formalin and stained with methylene blue to visualizethe plaques.

B. Results

1. 3G4 Inhibits Viral Spread of CMV

To investigate whether 3G4 has an inhibitory effect on CMV infection andreplication, confluent human fibroblasts were pretreated with 3G4 beforeCMV was added at a low m.o.i. The CMV used in these studies expressesgreen fluorescent protein (GFP). Hence, infected cells appear green whenobserved under a fluorescence microscope.

On day 3 of treatment, with both 50 μg/ml and 100 μg/ml of antibody,there are single infected cells both in untreated wells and in wellstreated with 3G4 or isotype-matched control antibody, GV39G. Thus,treating the fibroblasts with 3G4 does not appear to significantlyinhibit the entry of the virus into the cells.

On day 9, however, there is a dramatic difference in the number ofinfected cells in 3G4-treated vs. control, GV39G-treated wells (FIG. 9Aand FIG. 9B; compare top right panel to middle and bottom right panels).While the virus has spread to approximately 80% of the monolayer in thecontrol wells, the virus is restricted to the original singly-infectedcell in the 3G4-treated wells. Hence, 3G4 limits the spread of CMV fromthe original infected cell to the surrounding cells. This inhibition ofviral spread is observed when cells are treated with 100 μg/ml (FIG. 9A)and 50 μg/ml (FIG. 9B).

2. Viral Inhibition is Antibody Concentration-Dependent

In order to determine what concentration of 3G4 is necessary for theanti-viral effect at a low m.o.i., infected cells were treated withdifferent concentrations of 3G4 and the control antibody, GV39G. Asshown in FIG. 10, the complete inhibition of cell-to-cell spread isobserved with 3G4 at 100 μg/ml and 50 μg/ml. When the cells were treatedwith 25, 12.5 and 6.25 μg/ml of 3G4, there are increasing numbers of GFPpositive CMV-infected cells. Although 3G4 does not totally prevent viralspread from the primary infected cells at these lower concentrations, itstill has a meaningful anti-viral effect, since fewer GFP-positiveCMV-infected cells are seen in the 3G4-treated well as compared toGV39G-treated, control wells (FIG. 10).

3. Quantification of Viral Load at a Low M.O.I.

The anti-viral effect of 3G4 was quantitated by carrying out plaqueassays to determine the viral load following antibody-treatment. Thecontrols included untreated cells, the GV39G antibody and an additionalantibody control using the C44 antibody, a mouse IgG2a isotype antibodyto colchicine.

Treatment of infected cells (m.o.i.=0.01 pfu/cell) with 100 μg/ml of 3G4resulted in a dramatic 6 log₁₀ decrease in viral titer as compared tocontrol, GV39G-treated cells (FIG. 11A). This inhibition translates intoan approximately 99.9999% inhibition of viral replication. At aconcentration of 50 μg/ml, treatment with 3G4 results in a 3.5 log₁₀decrease in viral titer as compared to GV39G-treatment. Using 3G4 at 25μg/ml and 12.5 μg/ml, the results are still dramatic, and even at 6.25μg/ml an inhibitory effect is still observed (FIG. 11A).

4. Quantification of Viral Load at a High M.O.I.

3G4 treatment of fibroblasts infected at a high m.o.i. of 3 also resultsin a dramatic reduction in viral titer. At 100 μg/ml, treatment with 3G4resulted in a 5 log₁₀ decrease in viral titer as compared to control,GV39G-treated cells (FIG. 11B). At 50 μg/ml, 3G4 inhibited viralreplication by 3 logs when compared to GV39G (FIG. 11B).

5. Inhibition of Replication at a Late Stage

To determine which stage of the CMV replicative cycle is blocked by 3G4,a timed addition study was performed. For this, 3G4 was added tofibroblasts infected at a high m.o.i. at different time points after theinfection. The viral load (in both the cells and supernatant) wasquantified using a standard plaque assay.

Addition of 3G4 up to 24 hours after infection resulted in a 5-6 log₁₀decrease in viral titer (FIG. 11C). However, when addition of 3G4 wasdelayed to 48 hours, the inhibitory effect of 3G4 was reduced to 2 log₁₀and when addition was delayed to 72 to 96 hours, the inhibitory effectwas further reduced. This shows that 3G4 interferes with a late stage ofCMV replication that occurs between 24-48 hours after infection. Thus,3G4 does not significantly interfere with infection or with immediateearly or early gene expression. It rather acts later in the viralreplication cycle, e.g., on late gene expression, viral DNA synthesis,viral packaging or egress.

Example XIII Anti-Viral Effects of Anti-PS Antibodies Against RSV

In addition to the dramatic anti-viral effects against CMV shown inExample XII, the present example demonstrates the use of three differentanti-PS antibodies in the inhibition of Respiratory Syncitial Virus(RSV) replication.

A. Methods

1. Treatment of RSV-Infected Cells In Vitro

A-549 cells were grown to 100% confluence in three Costar 12-well tissueculture plates. 200 μL of minimum essential Eagle medium was added toall wells. Anti-phospholipid antibody (Ab) was added (100 μg in 100 μL)to 9 wells of each plate and 30 min. later cells in 6 of those initial 9wells were infected with an MOI of 1 with RSV long strain in a volume of100 uL. The three remaining wells were left as non-infected,antibody-treated wells. The three other wells with no antibody wereinfected with RSV at the same MOI as described above.

Each plate was used to test the three different antibodies: 3G4, 3SB and1B9 (Example IV). Cells were incubated in 5% CO₂ at 40° C. for 2 hoursand then 600 μL of medium was added to complete 1 mL volume in eachwell. An A-549 cell plate was kept in the same conditions, as control.Supernatants were collected at 4, 24 and 72 hours after infection. Ateach time point, four wells from each plate were sampled: one well withonly-Ab treated cells, two wells had Ab-treated/RSV-infected cells andone well had RSV-infected only cells. The samples were frozen at −80until the plaque assay.

2. Plaque Assays

The plaque assays were carried out as previously described (Kisch etal., 1963; Graham et al., 1988). Briefly, the frozen cells cellsuspensions were thawed quickly at 37° C. Three 10-fold dilutions weremade from the undiluted cell supernatants: 10⁻¹, 10⁻², and 10⁻³. 100 μLof each dilution plus the undiluted sample were inoculated into 80%confluent Hep-2 cell line plates, all in triplicates. Plates were placedin the 5% CO₂, 40° C. incubator for 5 days. On the 5^(th) day, theplates were developed and stained with hematoxylin and eosin to revealthe plaques in each well. The plaques were counted using a dissectingmicroscope to calculate the RSV viral load in pfu (plaque formingunits)/mL.

B. Results

As seen in FIG. 12, treatment of RSV-infected cells with either 3SB or1B9 resulted in a log decrease in viral replication. The anti-viraleffect was even more pronounced when the infected cells were treatedwith 3G4. Treatment with 3G4 resulted in a 2 log₁₀ decrease in viraltiter (FIG. 12). The inhibition was lower than seen with CMV, mostlikely because the concentration of 3G4 was low (25-50 μg/ml).

Example XIV Single Chain Anti-PS Antibodies

Given the many uses of anti-PS antibodies described herein, including asanti-tumor agents alone, as targeting agents for delivering attachedtherapeutic agents to tumors, and as anti-viral agents, the presentexample describes techniques suitable for generating single chain (scFv)anti-PS antibodies, i.e., wherein the V_(H) and V_(L) domains arepresent in a single polypeptide chain, generally joined by a peptidelinker.

A. Preparation of the Phage Antibody Library

The secondary stock of the bacterial library (about 1×10¹⁰ clones) wasinoculated into 100 ml 2×TY containing 100 μg/ml ampicillin and 1%glucose. It was grown with shaking at 37° C. until the OD at 600 nm was0.5.

M13KO7 helper phage was added at 10¹³ pfu and incubated without shakingin a 37° C. water bath for 30 min. The infected cells were centrifugedat 3,500 g for 10 min. The pellet was resuspended in 200 ml of 2×TYcontaining 100 μg/ml ampicillin and 75 μg/ml kanamycin and incubatedwith shaking at 30° C. overnight.

The culture was centrifuged at 10,800 g for 10 min. ⅕ volume PEG/NaClwas added to the supernatant, mixed well and left for 1 hr at 4° C. Itwas then centrifuged at 10,800 g for 30 min. The pellet was resuspendedin 40 ml PBS and 8 ml PEG/NaCl was added. It was mixed and left for 20min at 4° C. It was then centrifuged at 10,800 g for 10 min and thesupernatant aspirated. The pellet was resuspended in 2 ml 10% humanserum and centrifuged at 11,600 g for 10 min a microcentrifuge to removemost of the remaining bacterial debris.

To pre-pan, the phage antibody library in 10% human serum was added tothe PC coated dish and incubated for 60 min at room temperature.

B. Selection on Biotinylated Liposomes

20 μmol phosphatidylinositol and 20 μmol biotinylated phosphatidylserinewere dissolved in 10 ml hexane. This solution was dried to a thin layeron the surface of a flask using a rotating evaporator. 2 ml PBS wasadded and bath sonicated 4° C. for 30 minutes.

100 μl phage scFv and 100 μl biotinylated liposomes were then mixed inthe presence of 10% human serum and gently rotated for one hour at roomtemperature. Blocking was done with 100 μl streptavidin M-280 dynabeadsby adding 600 μl 2.5% casein/0.5% BSA for 30 min at room temperature.The beads were separated from the blocking buffer with a MPC-E (MagneticParticle Concentrator from Dynal) for 4-5 min.

The beads were resuspended in 100 μl PBS. 100 μl of blocked streptavidinDynabeads was added to the phage bound to the biotinylated antigen andgently rotated for 15 min at room temperature. Separation was achievedwith a MPC-E for 5 minutes and the supernatant poured off. It was washedfive times with 1 ml PBS. For each wash, the beads were resuspended andbrought down with a MPC-E.

Finally, the phage was eluted from the beads by resuspending in 300 μl100 mM triethalamine for 30 mins. 150 μl 1 M Tris pH=7.4 was added forneutralization. The beads were separated again with the MPC-E.

150 μl of the phage supernatant was used to infect 10 ml TG1 bacteria inlog phase. The 10 ml culture was shaken in the presence of 20 μg/mlampicillin at 37° C. for one hour. Ampicillin was added to the finalconcentration of 50 μg/ml and shaken for another hour. 10¹³ pfu M13helper phage was added to this culture, transferred to 100 ml 2TY mediumcontaining 100 μg/ml ampicillin and shaken at 37° C. for one hour.Kanamycin was added to the final concentration of 100 μg/ml and shakenat 30° C. overnight.

The phage preparation procedure was repeated and the selection procedurerepeated another 3 to 4 times.

C. Monoclonal Single Chain Antibody ELISA

Individual HB2151 colonies from the plates (after 4 rounds of selection)were inoculated into 500 μl 2×TY containing 100 μg/ml ampicillin and 1%glucose in 96-well plates and grown with shaking (300 rpm.) overnight at37° C. 5 μl from this plate were transferred to a second 96-well platecontaining 500 μl 2×TY containing 100 μg/ml ampicillin per well andgrown shaking at 37° C. for 3 hr (OD600=0.9).

To each well was added 50 μl 2×TY containing 100 μg/ml ampicillin, 10 mMIPTG (final concentration is 1 mM), which was grown with shakingovernight at 30° C. It was centrifuged at 1,800 g for 10 min and 100 μlof the supernatant used in the following ELISA.

96 well plates (DYNEX IMMULON® 1B) were coated with PS dissolved inethanol at a concentration of 10 μg/ml (P6641 10 mg/ml solvent wasChloroform:MeOH 95:5). 10 μg/ml PC was coated in the same way. Theseplates were evaporated at 4° C. in the cold room. 250 μl 2.5% casein wasadded to each well, and the plates were covered and blocked at 37° C.for 1 hour.

Wells were rinsed 3 times with PBS, 100 μl/well 10% human serum and 100μl/well supernatant containing soluble scFv was added and incubated for60 min at 37° C. The solution was discarded and washed 6 times with PBS.100 μl 9E10 in 5% casein/0.5% BSA-PBS (1:5000 dilution) was added toeach well, incubated at 37° C. for 1 hour and washed 6 times with PBS.100 μl HRP-goat-anti-mouse antibody (1:10000 dilution) was added to eachwell, incubated at 37° C. for 1 hour and washed 5 times with PBS. 100 μl0.05% OPD was added to each well and developed for 5 minutes. 100 μl0.18 M H₂SO₄ was added to stop the reaction and read at O.D. 490.

Antigen-positive clones were streaked on 2×TYAG plates and grownovernight at 30° C. Positive single colonies were picked into 3 ml2×TYAG media and grown 12 hours at 37° C. Plasmids were extracted andscFv gene inserts checked by enzyme digestion and PCR. The ones with thecorrect size inserts were sequenced.

The colonies with the correct size inserts were grown into 100 ml 2×TYAGmedia and shaken at 37° C. OD 600=0.5. These were transferred into 900ml 2×TYA and grown until OD 600=0.9. 1 M IPTG was added to a finalconcentration of 1 mM and shaken at 30° C. overnight. The supernatantwas checked using the same ELISA method as previously. The scFv proteinwas purified from the periplasmic fraction using Ni⁺⁺-agarose affinitychromatography.

D. Results

After 4 rounds of panning, the following clones gave promising ELISAsignal on PS plates and have the correct size insert: 3E5, 3A2, G5, C8,E4 and 4D5. These have been subcloned, wherein E4 gave 5 positivesubclones and 4D5 gave 5 positive subclones (Table 14).

TABLE 14 ELISA on PS Plate 0.099 0.107 0.118 0.115 0.100 0.094 0.0840.086 0.166 0.164 0.102 0.191 0.113 0.106 0.127 0.150 0.128 0.097 0.0780.087 0.190 0.144 0.102 0.154 0.122 0.115 0.117 0.112 0.105 0.097 0.0850.088 0.230 0.071 0.168 0.150 0.107 0.108 0.121 0.123 0.107 0.101 0.0830.085 0.191 0.246 0.186 0.150 0.138 0.121 0.114 0.131 0.100 0.096 0.0820.079 0.183 0.187 0.275 0.171 0.118 0.115 0.116 0.132 0.099 0.094 0.0820.086 0.185 0.073 0.208 0.102 0.111 0.176 0.126 0.118 0.096 0.087 0.1230.087 0.144 0.226 0.112 0.126 0.102 0.107 0.131 0.125 0.089 0.102 0.0820.084 0.188 0.073 0.142 0.151 3E5 3A2 G5 C8 E4 4D5

Once the positive clones were identified, they were sequenced. The ScFvnucleic acid and protein sequence of clone 3A2 is set forth in SEQ IDNO:5 and SEQ ID NO:6, respectively. The positive clones were grown up ona large scale and the scFv purified using Nickel agarose affinitychromatography. The purified scFv has been obtained using Phast-gelelectrophoresis.

Example XV Synthesis of PE-Binding Peptide Derivatives

The present example concerns the design and synthesis of exemplaryPE-binding peptide derivatives and conjugates for use in treating tumorsand viral diseases. The structures for exemplary duramycin derivativesare set forth in the panels of FIG. 13A through FIG. 13O, which matchthe following description.

A. DLB

0.5 mg (0.25 μmole) of duramycin dissolved in 0.387 ml 0.1M NaHCO₃ inwater was added to 0.113 mg (0.25 μmole) of NHS-LC-Biotin (Sigma). Thereaction mixture was incubated at room temperature for 1 hr and then at4° C. overnight. The sample was loaded onto a silica column, washed with0.1% trifluoroacetic acid (TFA), eluted with 0.1% TFA and 70% CH₃CN. Theeluant was collected and concentrated by centrifugation. The total yieldwas 0.5 mg (FIG. 13A).

B. DIB

0.5 mg (0.25 μmole) of duramycin dissolved in 0.286 ml of 0.1M NaHCO₃ inwater was added to 0.034 mg (0.25 μmole) of 2-iminothiolanehydrochloride (2-IT). The mixture was incubated at room temperature for1 hr. 0.13 mg (0.26 μmole) of iodoacetyl-LC-Biotin (Pierce) was addedand the reaction incubated at room temperature for 1 hr and at 4° C.overnight. The sample was loaded onto a silica column, washed with 0.1%TFA, eluted with 0.1% TFA and 70% CH₃CN. The eluant was collected andconcentrated by centrifugation. The total yield was 0.5 mg (FIG. 13B).

C. (DLB)₄NA

1.9 mg (0.94 μmole) duramycin was dissolved in 0.5 ml of 0.1M NaHCO₃ inwater. To this, 0.4 mg (0.88 μmole) NHS-LC-Biotin (Sigma) in 200 μldimethylformamide (DMF) was added. The mixture was incubated at roomtemperature for 4 hr. 10 mg (0.17 μmole) neutravidin (NA) in 1 ml wasadded to the reaction mixture, which was incubated at room temperaturefor 2 hr and then at 4° C. overnight. The reaction mixture was thenloaded onto a G-25 column (volume 50 ml) in PBS buffer. The fractionswere collected and analyzed by SDS PAGE (phast gel). Protein-containingfractions (7-16) were pooled together sterilized by filtration through a0.22 μm filter and the concentration determined by measuring absorptionat 280 nm. The total yield was 5.1 mg.

The sample was then fractionated by FPLC. Three peaks were collectedthat corresponded to the following: peak 1: [(DLB)₄NA]₃ (fractions17-23); peak 2: [(DLB)₄]₂ (fractions 24 33) and peak 3: (DLB)₄NA(fractions 35-48). All the samples were sterilized by filtration througha 0.22 μm filter. The final yields obtained were: 0.34 mg of[(DLB)₄NA]₃; 0.59 mg of [(DLB)₄]₂ and 1.41 mg of (DLB)₄NA (FIG. 13C).

D. (DLB)₄NA-F

0.61 mg of (DLB)₄NA in PBS buffer was added to 0.05 mgN-hydroxysuccinimidyl fluorescein (NHS-Fluorescein) (Sigma) in DMF. Themixture was incubated at room temperature for 1 hr. The reaction mixturewas then fractionated on a PD10 column (10 ml). (DLB)₄NA-F was eluted inthe protein-containing fractions (3 and 4), which were pooled togetherand sterilized by filtration through a 0.22 μm filter. The total yieldwas 0.5 mg (FIG. 13D).

E. (DIM)_(n) HIgG

Human IgG (HIgG) was first purified as follows: 1.3 ml HIgG (thatincluded 100 mg/ml HIgG, 22.5 mg/ml glycine and 3 mg/ml albumin inborate buffer with 1 mM EDTA, pH 9) was applied to an FPLC (S200, 250ml) column. The fractions were collected and analyzed by SDS PAGE on aphast gel. Fractions containing monomeric IgG (21-32) were pooledtogether and sterilized by filtration through a 0.22 μm filter. Thetotal yield as determined by absorption at 280 nm was 111 mg.

Purified HIgG (55 mg in 13 ml of borate buffer, pH 9) was added to 1.003mg in 0.5 ml of SMCC (Pierce) in DMF. The mixture was incubated at roomtemperature for 1 hr. At the same time, another reaction mixturecontaining 6 mg duramycin (3 μmole; dissolved in 0.5 ml 0.1M NaHCO₃) and0.413 mg 2-IT (3 μmole; in 0.1M NaCO₃) was incubated at room temperaturefor 1 hr. After completion of the reactions, the two reaction mixtureswere combined and incubated at room temperature for 2 hr and at 4° C.overnight. The reaction products were analyzed by SDS PAGE on a phastgel. The reaction products were loaded onto an FPLC column in boratebuffer, pH 9. The FPLC fractions corresponding to trimer (5-14), dimer(15-24), and monomer (25-37) were pooled and sterilized by filtrationthrough a 0.22 μm filter. The total yield of monomer was 54.6 mg. Fiveto seven duramycin groups were attached to each molecule of HigG (FIG.13E).

F. (DIM)_(n) HIgG-F

1 mg (0.7 ml) of (DIM)_(n)HIgG was added to 5 μl of NHS-Fluorescein inDMF. The reaction mixture was incubated at room temperature for 1 hr anddesalted on a PD-10 column. Protein-containing fractions (2-3) werepooled and sterilized by filtration through a 0.22 μm filter. The totalyield was 0.9 mg (FIG. 13F).

G. (DIM)_(n) HIgG-B and [(DIM)_(n)HIgG]₂-B

To synthesize biotinylated derivatives of [(DIM)_(n)HIgG]₂, 0.66 mg (1ml) of [(DIM)_(n)HIgG]₂ was added to 8 μl of 1 mg/ml of NHS-LC-Biotin(Pierce) in DMF. The mixture was incubated at room temperature for 1 hr.The reaction mixture was then desalted on a PD-10 column.Protein-containing fractions (3 and 4) were pooled and sterilized byfiltration through a 0.22 μm filter. The final yield was 0.46 mg.

The biotinylation of the monomer (DIM)_(n)HIgG was performed in the samemanner. Briefly, 1.06 mg (0.75 ml) of (DIM)_(n)HIgG were added to 12 μlof 1 mg/ml NHS-LC-Biotin in DMF. After incubation at room temperaturefor 1 hr, the reaction product was desalted on a PD-10 column.Protein-containing fractions (3 and 4) were pooled and sterilized byfiltration through a 0.22 μm filter. The final yield was 0.62 mg (FIG.13G).

H. (DIB)₄NA

2 mg (0.99 μmole) of duramycin were dissolved in 0.5 ml 0.1M NaHCO₃ andadded to 0.136 mg (0.99 μmole) of 2-IT. The reaction mixture wasincubated at room temperature for 1 hr. Following this, 0.483 mg (0.95μmole) of iodoacetyl-LC-Biotin (Pierce) was added and the reactionmixture incubated at room temperature for 1 hr. 10 mg (0.17 μmole) ofneutravidin in 1 ml of H₂0 was added and incubated at 4° C. overnight.The reaction mixture was fractionated by FPLC. Three different peakswere collected and pooled: [(DIB)₄NA]₃ (fractions 17-23); [(DIB)₄NA]₂(fractions 24-33); and (DIB)₄NA (fractions 35-48). All the samples weresterilized by filtration through a 0.22 μm filter. The total yieldsobtained were 0.87 mg of [(DIB)₄NA]₃; 1.25 mg of [(DIB)₄NA]₂; and 1.83mg of (DIB)₄NA (FIG. 13H).

I. (DIB)₄NA-B

0.023 mg (0.3 μmole) of (DIB)₄NA was added to 0.9 μg of NHS-LC-Biotin(Pierce). The reaction was incubated at room temperature for 1 hr andthen desalted on a PD-10 column. The total yield was 0.04 mg (FIG. 13I).

J. DS-1

5 mg (2.5 μmole) of duramycin dissolved in 0.5 ml of 0.1M NaHCO₃ inwater was added to 0.319 mg (2.6 μmole) of 1,3 propane sultone. Themixture was incubated at 4° C. overnight. The sample was loaded onto asilica column, washed with 0.1% TFA, eluted with 0.1% TFA and 70% CH₃CN.The eluant was collected and concentrated by centrifugation underreduced pressure. The total yield was 5 mg (FIG. 13J).

K. DS-2

1 mg (0.497 μmole) of duramycin dissolved in 0.3 ml of 0.1M NaHCO₃ inwater was added to 0.072 mg (0.523 μmole) of 2-IT. The reaction mixturewas incubated at room temperature for 1 hr. 0.125 mg (0.49 μmole) ofSBF-Chloride (Pierce) was added. The reaction mixture was incubated atroom temperature for 1 hr and 4° C. overnight. The peptide was purifiedon a silica column. The eluant was collected and concentrated bycentrifugation under reduced pressure. The total yield was 1 mg (FIG.13K).

L. DS-3

1 mg (0.497 μmole) of duramycin dissolved in 0.4 ml of 0.1M NaHCO₃ inwater was added to 0.109 mg (0.592 μmole) of 2-sulfobenzoic acid cyclicanhydride. The reaction was incubated at room temperature for 1 hr and4° C. overnight. The peptide was purified on a silica column. The eluantwas collected and concentrated by centrifugation under reduced pressure.The total yield was 1 mg (FIG. 13L).

M. DS-4

0.25 mg (0.124 μmole) of duramycin dissolved in 0.5 ml of 0.1M NaHCO₃ inwater was added to 0.017 mg (0.124 μmole) of 2-IT. The reaction mixturewas incubated at room temperature for 1 hr. The mixture was then addedto 0.049 mg (0.124 μmole) Ellman's reagent. The mixture was incubated atroom temperature for 2 hr and overnight at 4° C. 250 μl of 1 mg/ml of4-Amino-5-hydroxy-2,7-naphthalene disulfonic acid mono-sodium salthydrate was added to 100 μl of 1 mg/ml 2-IT. The reaction was incubatedat room temperature for 1 hr. 50 μl of this reaction mixture was addedto the previous reaction and incubated at room temperature for 1 hr. Thepeptide was purified on a silica column. The eluant was collected andconcentrated by centrifugation under reduced pressure (FIG. 13M).

N. DS-5

5 mg (2.5 μmole) of duramycin dissolved in 0.5 ml of 0.1M NaHCO₃ inwater was added to 0.356 mg (2.6 μmole) of 1,3 butane sultone. Themixture was incubated at 4° C. overnight. The sample was loaded onto asilica column, washed with 0.1% TFA, eluted with 0.1% TFA and 70% CH₃CN.The eluant was collected and concentrated by centrifugation underreduced pressure. The total yield was 5 mg (FIG. 13N).

O. DC-1

0.25 mg (0.124 μmole) of duramycin dissolved in 0.5 ml of 0.1M NaHCO₃ inwater was added to 0.017 mg (0.124 μmole) of 2-IT. The reaction mixturewas incubated at room temperature for 1 hr. The mixture was then addedto 0.049 mg (0.124 μmole) Ellman's reagent. The mixture was incubated atroom temperature for 2 hr and overnight at 4° C. The peptide waspurified on a silica column. The eluant was collected and concentratedby centrifugation under reduced pressure (FIG. 13O).

Example XVI Duramycin Derivatives Specifically Bind PE

The present example shows that the duramycin derivatives synthesized inExample XV are specific for PE and can therefore be used as designed, bylinking to cell-impermeant, targeting or anti-viral agents and use inthe treatment of tumors and viral diseases.

To test the specificity of the duramycin derivatives, particularly thebinding to PE in preference to other phospholipids, a series ofcompetition ELISAs were performed. The ability of the duramycinderivatives to compete with either DIB or DLB for binding to PE wastested in the following method.

PE and PC were dissolved separately in ethanol. The final concentrationwas 5 μg/ml. 100 μl was added to each well of 96 well ELISA plates(DYNEX IMMULON®1B). These plates were evaporated at 4° C. in a coldroom. 250 μl 2.5% casein was added to each well, covered and blocked at37° C. for 1 hour. The blocking buffer was discarded and 100 μl 2.5%casein added to each well. The duramycin compound was added as a serialdilution across the plate, such as (DIM)nHIgG, (DIB)4NA, (DLB)4NA, DS,duramycin and DIB.

The (DIM)nHIgG starting concentration was 1.4 mg/ml, the (DIB)4NAstarting concentration was 800 μg/ml, and the (DLB)4NA startingconcentration was 800 μg/ml. These were incubated at 37° C. for 1 hourand washed 5 times with PBS. 100 μl HRP-streptavidin (1:5000 dilution)was added to each well, incubated at 37° C. for 1 hour and washed 5times with PBS. 100 μl 0.05% OPD was added to each well and developedfor 5 minutes. 100 μl 0.18 M H2SO4 was added to stop the reaction andread at O.D. 490.

The resultant data was tabulated and then plotted graphically. Asexemplified by the data in FIG. 14C and FIG. 14D, increasingconcentrations of the duramycin derivatives decrease absorbance at 490nm, showing that the duramycin derivatives compete with DIB and DLB forbinding to phosphatidylethanolamine.

The phospholipid binding profiles of duramycin constructs were confirmedusing further ELISAs. The respective test lipids PS, PE, PI, CL, PC, PG,SM, and cholesterol were dissolved separately in ethanol and used tocoat ELISA plates. Duramycin compounds were added as serial dilutionsacross the plates. After incubation and washing steps, a secondarydetection reagent was added to each well and reactivity determined usingthe colorimetric assay as described above.

Representative phospholipid binding profiles for the duramycin biotinderivatives, DIB and DLB are depicted in FIG. 14A. It is shown that DIBand DLB are specific for PE, with binding to each of PS, PI, CL, PC, PGand SM being negligible or undetectable. (DIM)_(n)HIgG-B and[(DIM)_(n)HIgG]₂-B had essentially the same binding profile as DLB.Although minimal binding to PS was observed at high concentrations ofDIB (FIG. 14A), this is not meaningful in the context of this study, asbinding to PS was undetectable at DIB concentrations that weresaturating and half maximal for PE binding. Therefore, the duramycinconstructs specifically bind to phosphatidylethanolamine.

It was also shown that serum has no significant effect on PE binding byduramycin derivatives. This is exemplified by binding of the duramycinbiotin derivative, DLB to PE-coated ELISA plates in the presence andabsence of serum (BSA), wherein the binding profiles show no significantdifferences (FIG. 14B).

Example XVII Anti-Viral Effects of PE-Binding Peptide Derivatives

In addition to the anti-viral effects mediated by anti-PS antibodies, asshown in Example XII and Example XIII, the present example demonstratesthe anti-viral effects of peptide derivatives that specifically bind tothe other common aminophospholipid, PE.

A. Methods

1. Treatment of CMV-Infected Cells In Vitro

Confluent monolayers of human diploid foreskin fibroblasts (HHF-R2) in6-well plates were infected with human CMV AD169 expressing greenfluorescent protein (GFP) at an MOI=0.01 as described in Example XII(Bresnahan et al, 1996). The cells were incubated with virus in a totalvolume of 1.5 ml per well at 37° C. for 90 minutes. During theinfection, the plates were gently rocked every 30 minutes. Following theinfection, the cell supernatant was removed and DMEM/10% FBS/pen-strep(2 ml per well) was added to each well.

Different dilutions of duramycin derivatives (DLB)₄NA, (DIM)_(n)HIgG,DS-1, DS-2, DS-3 and DC-1 were added to the wells before the addition ofthe virus, and following infection. The infected cells were incubated at37° C. for a total of 14 days. The medium and duramycin derivative ineach well were replaced every 3 days.

2. Fluorescent Microscopy

As in Example XII, the recombinant CMV expresses GFP under the controlof the SV40 promoter. Hence, infected cells appear green under afluorescent microscope. In these studies, the CMV-infected cells treatedwith the duramycin derivatives were observed under a fluorescentmicroscope at days 4 and 6.

B. Results

On day 4, there are single infected GFP-positive green cells inuntreated wells and wells treated with (DLB)₄NA and (DIM)_(n)HIgG (FIG.15, left panels). Thus, treatment of HHF-R2 cells with these duramycinderivatives does not appear to inhibit the entry of the virus into thecells. There is some preliminary evidence that the duramycin derivativesDS-1, DS-2 and DS-3 inhibit viral entry into the cells.

On day 6 after treatment with (DLB)₄NA and (DIM)_(n)HIgG, there is amarked difference in the number of infected GFP-positive cells inuntreated vs. the duramycin derivative treated wells (FIG. 15, middlepanels). By day 6, the virus has spread from the single infected cellseen on day 4 surrounding cells in the untreated wells (FIG. 15, top,compare left panel to middle panel). However, on day 6 in the wellstreated with (DLB)₄NA and (DIM)_(n)HIgG, the virus is limited to theoriginal singly infected cell (FIG. 15, middle and bottom, compare leftpanels to middle panels).

Accordingly, (DLB)₄NA and (DIM)_(n)HIgG limit the spread of CMV from theoriginal infected cell to the surrounding cells. This inhibition ofviral spread is observed when cells were treated with differentconcentrations of (DIB)₄NA (100 μg/ml and 50 μg/ml) and (DIM)_(n)HIgG(200 μg/ml and 100 μg/ml).

Example XVIII Advantages of 3G4 Antibody

The 3G4 antibody developed by the inventors' unique protocol, asdescribed in Example IV, has many advantages over the anti-PS antibodiesin the literature, including the prominent anti-PS antibody, 3SB (Roteet al. (1993). The present example describes certain of thoseadvantages.

A. Class and Specificity

3G4 is an IgG antibody, whereas 3SB is IgM. Antibodies of IgG class havenumerous advantages over IgM, including higher affinity, lower clearancerate in vivo and simplicity of purification, modification and handling.A comparison of the PS binding of the IgM antibody, 3SB, with 3G4 andanother IgG antibody is shown in FIG. 19A and FIG. 19B.

3G4 reacts strongly with the anionic phospholipids PS, PA, PI, PG and CLwith approximately the same intensity, and binds to theaminophospholipid, PE less strongly. It has no reactivity with PC and SMand has the binding specificity profile: PS=PA=PI=PG>CL>>PE (Example IV;Table 4). 3G4 does not bind detectably to heparin, heparan sulfate or todouble or single stranded DNA, nor to cellular proteins extracted frombEnd.3 cells on Western blots. The binding of 3G4 is unaffected by thepresence of 5 mM EDTA, showing that Ca²⁺ is not require for 3G4 bindingto anionic phospholipids. 3G4 did not bind to ELISA plates that had beencoated with phospholipids but then washed with 0.2% Tween 20 in saline,confirming that the binding was to the absorbed phospholipid.

The phosphoglycerol core of the anionic phospholipids is the same inphospholipids from all mammalian species. The 3G4 antibody reacts withboth mouse and human phospholipids, which is important for pre-clinicaland clinical development. 3G4 is more specific for anionic phospholipidsthan the natural ligand, annexin V. Unlike 3G4, annexin V also bindsstrongly to neutral phospholipids in physiological concentrations ofCa²⁺.

The specificity of 3G4 for anionic phospholipids was confirmed by assaysin which liposomes formed from different phospholipids were used tocompete for 3G4 binding to immobilized PS. Liposomes were prepared fromsolutions of 5 mg of a single phospholipid in chloroform. The solutionswere dried under nitrogen to form a thin layer in a round-bottomed glassflask. Ten ml of Tris buffer (0.1 M, pH 7.4) were then added and theflask was sonicated five times for 2 min. The 3G4 antibody (0.1 μg/ml)was added to either buffer or different phospholipid liposomes andpre-incubated for 30 minutes at room temperature. The mixture was addedto PS-coated plates (after standard blocking), incubated for 1 hour,washed and the secondary antibody added. After 1 hour, the plates werewashed and developed for 5 minutes using OPD.

As shown in Example IV, 3G4 binds to PS, PA, PI, PG and CL whenimmobilized and binds to immobilized PE to a lesser degree, but does notbind to immobilized PC. The ability of 3G4 to bind to immobilized PS inthe presence or absence of the different liposomes is shown in FIG. 20.Results from these liposome competition studies show that binding of 3G4to PS adsorbed to ELISA plates was blocked by liposomes prepared fromPS, PA, PI, PG and CL, but that liposomes prepared from PE and PC didnot result in a detectable reduction in 3G4 binding (FIG. 23). Also, SMliposomes were not inhibitory.

B. Inhibition of Cell Proliferation

3G4 binds to activated, dividing, injured, apoptotic and malignant cellsthat externalize PS and other anionic phospholipids. The 3G4 antibodyinhibits the proliferation of endothelial cells in vitro, and shows amarked selective inhibition of dividing endothelial cells as opposed toquiescent cells.

The effect of the anti-PS antibodies 3G4, 9D2, 3B10, 1B9, 2G7, 7C5 and3SB on the growth of bEnd.3 cells in vitro was determined, bEnd.3 cells(10,000/well) were seeded in 48 well plates and allowed to attach. 20%DMEM alone (control) or 20% DMEM containing the antibodies (20 μg to 40μg total IgG per well) was added 4 hours after seeding. Each clone wastested on two separate plates in triplicates. Cells were detached 48 and96 hours later, the cell count was determined in each well and theaverage cell number per treatment was calculated.

The 3G4 and 9D2 antibodies were particularly effective, followed by 3SBand 3B10, with 1B9, 2G7 and 7C5 having less inhibitory effects. Each ofthe antibodies show a selective inhibition of dividing (subconfluent)endothelial cells as opposed to quiescent (confluent) cells. Incomparative studies, 3G4 showed the greatest inhibitory effect, followedby 9D2, each of which were more inhibitory than 3SB (FIG. 16).

C. Anti-Tumor Effects

3G4 binds to the surface of tumor vascular endothelial cells in vivo.When injected intravenously into mice bearing various tumors, 3G4specifically and consistently localized to the tumor, but not to normalorgans. Staining was observed on tumor vascular endothelium (FIG. 22),necrotic areas and individual malignant cells. There are multiplebinding sites for 3G4 in tumors, which allows simultaneous targeting ofboth tumor endothelial and tumor cells.

3G4 suppresses angiogenesis and tumor growth in vivo and shows nodetectable organ toxicity in tumor-bearing mice. In initial studies, 3G4has shown impressive anti-tumor effects in syngeneic and xenogeneictumor models, wherein the antibody causes tumor vascular injury,decrease in vascularity and tumor necrosis (Example XI). Regressions ofestablished tumors have been observed in 30% to 50% of the animalstreated.

Representative anti-angiogenic and vascular targeting effects of the 3G4antibody are shown in FIG. 17A and FIG. 17B, respectively. Analyses oftumor sections from nude mice bearing MDA-MB-231 orthotopic tumorstreated with 3G4 revealed anti-angiogenic effects in all treated tumors.FIG. 17A shows representative images of tumors from mice treated with3G4 as opposed to control antibodies. The control tumor shows no signsof necrosis and is highly vascularized, as demonstrated by thepan-endothelial cell marker, CD31, detected on tumor blood vessels (FIG.17A, left panel). In contrast, tumors from the mice treated with 3G4have 80 to 90% necrosis and almost complete disappearance ofCD3′-positive structures, indicating that the treatment produced asubstantial anti-angiogenic effect (FIG. 17A, right panel).

Another component of the anti-cancer activity of 3G4 is the induction oftumor vascular damage. This is illustrated in FIG. 17B, which providesrepresentative images of H&E stained tumors derived from the samecontrolled study. The blood vessels in the control tumors are wellperfused, morphologically intact and surrounded by viable dividing tumorcells (FIG. 17B, left panel). In contrast, the blood vessels in the3G4-treated animals are frequently observed to have a disintegratingendothelial layer and are blocked by the detached endothelial cells and,likely, by host cells that are attracted to the denuded vessels (FIG.17B, right panel). The representative vessel in the 3G4-treated tumorclearly shows loss of function, as indicated by the pre-necrotic layerof surrounding tumor cells (FIG. 17B, right panel).

In summary, the histological examination following the treatment oforthotopic MDA-MB-231 tumors using 3G4 shows: 1) disintegration ofvascular endothelium in about 50% of vessels in the tumor; 2) attachmentof leukocytes to tumor endothelium and infiltration of mononuclear cellsinto the tumor interstitium; 3) occlusion of tumor vessels by plateletaggregates and red cells; 4) a 70% reduction in microvascular density intumors from 3G4 treated vs. untreated mice; and 5) central necrosis ofthe tumors, with survival of a peripheral rim of tumor cells, typical ofa VTA. Thus, a primary anti-tumor action of the 3G4 antibody is exertedthrough effects on tumor vasculature. Other mechanisms, particularlyantibody-dependent cellular cytotoxicity directed against the tumorcells themselves, likely contributes to the anti-tumor effect. This isimportant, and may permit killing of more tumor cells, including thosein the peripheral rim.

In follow-up studies, the effect of 3G4 on tumor growth has beenexamined in other murine models, including syngeneic (mouse Meth Afibrosarcoma), subcutaneous xenografts (L540 human Hodgkin's lymphoma)and orthotopic tumors (human MDA-MB-231 breast cancer and humanMDA-MB-435 breast cancer). Treatment of mice with 3G4 antibody resultedin 90%, 65% and 50% and 70% growth retardation of these tumors,respectively. Both small (0.1 cm diameter) and well-established (0.3 cmdiameter, 200 mm³) tumors were inhibited alike. Anti-PS treatmentinduced long-term complete remissions in 50% of Meth A-bearing mice and30% of mice with MBA-MD-231 tumors. 3G4 has the highest inhibitoryeffect in immunocompetent mice. The orthotopic models of human breasttumors (MDA-MB-231 and MDA-MB-435), in which human breast tumors aregrown in the mammary fat pads of mice, are important as these arepractical and realistic models of human breast cancer growing within thebreast of humans.

D. Safety Profile

The 3G4 antibody is different to anti-phospholipid antibodies describedin the literature. Typically, anti-phospholipid antibodies are regardedas pathogenic antibodies that interfere with the coagulation cascade.They inhibit coagulation reactions in vitro and cause thrombosis invivo. In contrast, 3G4, 9D2 and like antibodies are therapeuticantibodies without pathogenic effects.

1. Coagulation

A certain aspect of 9D2 and like antibodies stems from the inventors'realization that desirable antibodies should preferably be selectedusing a screen to identify antibodies that bind to PS-coated plates asstrongly in the presence of serum as in the absence of serum.

In studies of blood coagulation in vitro, a weak inhibition of TissueFactor (TF)-induced coagulation was observed using high doses of 3G4antibody. In other studies using lower doses, recalcified plasma from3G4 treated mice coagulated at the same rate as did recalcified plasmafrom BBG3 treated mice in the presence of tissue factor. Also, theaddition of 100 μg/ml of 3G4 to cells plus tissue factor in vitro didnot affect the generation rate of coagulation Factor Xa in proplex(extrinsic coagulation pathway).

Despite the weak inhibition of TF-induced coagulation using highantibody levels in vitro, the 3G4 antibody has been tested in vivo anddoes not cause thrombotic complications in normal or tumor-bearing mice(e.g., see Example XI). The 3G4 antibody has also been tested in monkeysin vivo and no significant side effects have been observed.

2. Other Indicators of Low or No Toxicity

The first evidence that 3G4 has no or low toxicity in mice came from thefinding that 3G4 grows as a hybridoma in mice without evidence oftoxicity. Also, when 1 mg of purified 3G4 was injectedintraperitoneally, no toxicity was observed.

Systematic in vivo studies have now been conducted in which groups ofthree 8 week old BALB/c mice were injected IP with 100 μg of purified3G4 or with an isotype-matched control IgG₃ (BBG3) three times a weekfor 2 to 3 weeks. No physical signs of toxicity have been observed, andno histopathological signs of organ toxicity or morphologicalabnormalities have been detected in sections of major organs removedfrom 3G4-treated mice. The following parameters were specificallyexamined.

In terms of bodyweight, 3G4-treated mice gained weight at the same rateas BBG3 treated mice. No weight loss was observed in the earlierstudies. There were no physical signs of toxicity, e.g. hair loss, lossof appetite, etc. There are no changes in blood cell counts, includingred cells, platelets, white cells, absolute lymphocyte counts orabsolute neutrophil counts. To analyze bone marrow cellularity, paraffinsections of bone marrow derived from 3G4 or BBG3-treated mice (sixinjections, 100 μg) were examined for total cellularity and cellularcomposition. Marrows in the treated animals were essentially completelycellular (as would be expected for a young mammal). Erythroid,granulocytic, lymphocytic progenitors and megakaryocytes were present innormal numbers.

In summary, no instance of toxicity has been observed in more than 200mice treated with high doses of 3G4 (0.1 mg) three times a week for 2-3weeks. Even when doses as high as 2 mg were given, no signs of toxicitywere seen. Mice retain normal physical signs, bone marrow cellularity,white blood cell counts, histology and coagulation functions.

The 3G4 antibody has also been administered to monkeys in safety studiesand no side effects have been observed.

Blood clearance kinetic studies have also been conducted in mice. 3G4was radioiodinated using the Bolton Hunter reagent and was injectedintravenously into mice (25 g). Samples of blood were removed via thetail vein at various later time points. The blood clearance rate of 3G4was typical of a mouse IgG in the mouse. The half-life in the α-phase ofclearance was 3 hours while that in the β-phase was 5 days. Volume ofdistribution was normal (100 ml/kg). These studies indicate that 3G4does not interact with normal host tissues, leading to its acceleratedclearance.

E. Anti-Viral Effects

The 3G4 antibody also exerts significant anti-viral effects. As shown inseen in Example XIII, the treatment of RSV-infected cells with 3G4 wassuperior to the effect observed using 3SB. These results thereforehighlight another advantage of the 3G4 antibody over the prominentanti-PS antibody in the literature, 3SB (Rote et al. (1993).

The 3G4 antibody is also shown to be very effective in inhibiting CMV,both in vitro (Example XII) and in enhancing the survival of miceinfected with mCMV in vivo (Example XXI). In addition, the 3G4 antibodyis further shown to inhibit Pichinde virus infection, the infectiousagent of Lassa fever (Example XXIV). The cell surface PS exposure hereinshown to follow viral infection, and the ability of the 3G4 antibody tobind to cells infected with Vaccinia virus (Example XXIII), shows thatthe 3G4 antibody has enormous potential as a broad spectrum anti-viralagent.

Example XIX 3G4 Antibody, CDR Sequences and Chimera

The 3G4 antibody thus possesses the combined properties of ananti-angiogenic, anti-tumor vascular and anti-viral agent. Theinhibitory activities of 3G4 on cell division, angiogenesis, tumorgrowth and viral infectivity, taken together with lack of apparenttoxicity, show broad therapeutic indications for this antibody,including in the treatment of angiogenic disorders, cancer, diabetes andviral infections.

Antibodies recognizing substantially the same epitope as the 3G4antibody can be generated for use in one or more of the anti-angiogenic,anti-tumor vascular and anti-viral therapies, e.g., by immunization andconfirmed by antibody competition studies. Antibodies that bind toessentially the same epitope as the 3G4 antibody can also be generatedfrom a knowledge of the 3G4 antibody sequences provided herein. Thepresent example provides the sequences of the complementaritydetermining regions (CDRs) of the 3G4 antibody and the use of thesequence information.

A. 3G4 Antibody Sequences

The original sequences of the antibody variable regions were obtained byRACE from the hybridoma that produces the 3G4 antibody and the sequencesverified. The nucleic acid and amino acid sequences of the variableregion of the heavy chain (Vh) of the 3G4 antibody, encompassing CDR1-3,are represented by SEQ ID NO:1 and SEQ ID NO:2, respectively.

SEQ ID NO:1 and SEQ ID NO:2 include part of the mouse leader sequenceand constant chain sequences, as shown in FIG. 18A. The leader sequenceis represented by amino acids 1 through 19 of SEQ ID NO:2, and themature protein begins as shown by the arrow in FIG. 18A. The heavy chainCDR amino acid sequences encompassed by this variable region amino acidsequence are VH CDR1 of SEQ ID NO:10, VH CDR2 of SEQ ID NO:11 and VHCDR3 of SEQ ID NO:12. Sufficient complementarity determining regionsequence information is thus included by the sequence of the matureprotein up to the sequence portion concluding VSS, after which the aminoacids are not essential for antigen binding. As such, the BstEII site inthe nucleic acid sequence can be used as a convenient site to prepare afunctional mouse variable region, e.g., for use in grafting onto a humanconstant region (FIG. 18A).

In practice, the 3G4-2BVH sequence has been grafted onto a human γ1constant region at the BstEII site using a Lonza pEE vector. Theresultant product contains the mouse leader sequence and its VH isjoined to the human CH1 sequence in the manner shown in FIG. 18A,wherein ASTLGPSVFPLAPSSKSTSG (SEQ ID NO:7) represents the first part ofthe human CHI sequence.

The nucleic acid and amino acid sequences of the variable region of thelight chain (Vκ) of the 3G4 antibody, encompassing CDR1-3, arerepresented by SEQ ID NO:3 and SEQ ID NO:4, respectively. SEQ ID NO:3and SEQ ID NO:4 again include part of the mouse leader sequence andconstant chain sequences, as shown in FIG. 18B. The leader sequence isamino acids 1 through 22 of SEQ ID NO:4, and the mature protein beginsas shown by the arrow in FIG. 18B. The light chain CDR amino acidsequences encompassed by this variable region amino acid sequence are VLCDR1 of SEQ ID NO:13, VL CDR2 of SEQ ID NO:14 and VL CDR3 of SEQ IDNO:15. Sufficient complementarity determining region sequenceinformation is included by the sequence of the mature protein up to thesequence portion concluding TVF, after which the amino acids are notessential for antigen binding. As such, the BbsI site in the nucleicacid sequence can be used as a convenient site to prepare a functionalmouse variable region, e.g., for use in grafting onto a human constantregion (FIG. 18B).

In practice, the 3G4-2BVL sequence has been grafted onto a human κconstant region at the BbsI site using a Lonza pEE vector. The resultantproduct contains the mouse leader sequence and its VL is joined withinthe human CL1 sequence in the manner shown in FIG. 18B, whereinIFPPSDEQLKSGTAS (SEQ ID NO:8) represents the first part of the human κconstant region sequence.

B. Generation and Characterization of 3G4 Chimeric Antibody

The chimeric construct containing the murine complementarity determiningregions and the human constant regions has been produced (ch3G4) andshown to behave essentially the same as the original murine antibody.

The murine 3G4 antibody was converted into a human-mouse chimericantibody (Avanir (Xenerex) Biosciences, San Diego, Calif.). The murineV_(H) was cloned and grafted onto the human γ₁ constant region at theBstEII site of the Lonza 2BVH vector. The murine V_(K) was cloned andgrafted onto the human K constant region at the BbsI site of the Lonza2BVL vector. The sequences were verified. The entire construct wasexpressed in CHO cells and purified.

The resultant ch3G4 bound at least as did well as the murine 3G4 tophospholipid-coated ELISA plates. The in vitro binding profile ofchimeric 3G4 to the panel of phospholipids is shown in FIG. 21, whereinbinding to PS, PA, CL, PI and PG is shown to be similar. The binding wasantigen-specific since no binding was observed with control antibodiesof irrelevant specificity. In certain studies, an apparently greaterbinding of chimeric 3G4 vs. the 3G4 antibody was observed; this may bedue to superior binding of the secondary antibody.

In vivo, ch3G4 localizes to tumor vascular endothelium and exertsanti-tumor effects. The anti-tumor effects of ch3G4 in MDA-MB-435 humanbreast cancer cells growing in mice is described in Example XI and shownin FIG. 8G. Treatment of mice with MDA-MB-435 tumors using the chimericantibody effectively retarded tumor growth as opposed to control.

Localization of ch3G4 was examined in MDA-MB-435 human breast cancercells growing in mice. Mice were injected intravenously withbiotinylated ch3G4 or control IgG of irrelevant specificity. One hourlater, the mice were exsanguinated, and their tumours were removed andfrozen sections were cut. Biotinylated reagents were first incubatedwith streptavidin-Cy3 conjugate, washed in PBS, then incubated with MECA32 antibody followed by FITC-tagged secondary antibody. Single images,taken with appropriate filters for Cy3 (red) and FITC (green)fluorescence respectively, were captured by digital camera andtransferred to a computer. Converged images demonstrating yellow color(a product of merged green and red fluorescence) were superimposed withthe aid of Metaview software.

In this double staining method, the biotinylated proteins and thevascular endothelium are labeled by red and green. Where thebiotinylated proteins are bound to the endothelium, the converged imageappears yellow. As shown in FIG. 22, biotinylated ch3G4 binds to thetumor vascular endothelium, because the staining patterns converges withthat of MECA 32.

Example XX 3G4 Antibody in Combination Therapy with Docetaxel

The present example concerns combination therapies for tumor treatmentusing the 3G4 antibody and the chemotherapeutic drug, docetaxel. Theseagents are designed to attack tumor vasculature endothelial cell andtumor cell compartments, leading to synergistic treatment with lowertoxicity. The results showed that this combination therapy did indeedsignificantly enhanced treatment efficacy.

A. Fc Domain-Mediated Anti-Tumor Effects

The 3G4 antibody was tested for inhibitory effects on tumor cells invitro. No direct inhibitory effect on tumor cells was observed.Therefore, it is likely that the anti-tumor effects of the 3G4 antibodyinclude Fc domain-mediated augmentation of immune effector functionssuch as antibody mediated phagocytosis, ADCC, CDC and stimulation ofcytokine production, or these mechanisms combined.

The effects of 3G4 on the phagocytosis of PS-positive cells bymacrophages have been evaluated. Fluorescent tumor cells were treatedwith H₂O₂ to induce PS exposure. Treated and untreated cells were thenharvested and contacted with the 3G4 antibody or a control antibody(BBG). Mouse bone marrow macrophages were then added, and the ability ofthe macrophages to phagocytose the fluorescent tumor cells was analyzedusing a fluorescent microscope.

It was determined that 3G4 could increase the phagocytosis ofPS-positive cells by macrophages by more than three fold (FIG. 23). Thisfinding supports the inventors' reasoning that the Fc domain of the 3G4antibody contributes to the anti-tumor effects of the antibody. That is,the Fe domain activates host immune effector functions, which then exertanti-tumor effects. The 3G4 antibody should therefore enhance the lyticactivity of NK cells, leading to more effective ADCC.

B. Docetaxel Induces PS Exposure on Endothelial Cells

The induction of PS exposure on endothelial cells by subclinicalconcentrations of docetaxel was examined in vitro by FACS analysis.Human umbilical vein endothelial cells (HUVEC) and human microvesselendothelial cells (HMVEC) were treated with 10 nM of docetaxel for 24hrs and examined by FACS. Both treated HUVEC and HMVEC showedsignificant increase in 3G4 binding as compared to untreated cells (FIG.24A and FIG. 24B, respectively). Docetaxel incubations for 48 and 72 hrswere also conducted.

C. Docetaxel Induces PS Exposure on Tumor Cells

The in vitro induction of PS exposure by subclinical concentrations ofdocetaxel was also examined by FACS analysis using a panel of tumor celllines. Mouse lewis lung carcinoma 3LL, mouse colon carcinoma Colo26 andhuman breast cancer MDA-MB-435 cells were treated with 10 nM ofdocetaxel for 24 hrs and examined by FACS. All tumor cell lines testedshowed significant increase in 3G4 binding as compared with untreatedcells (FIG. 25A, FIG. 25B and FIG. 25C, respectively). Docetaxelincubations for 48 and 72 hrs were also conducted. Mouse melanoma B16and mouse firbrosarcoma Meth A tumor cell lines were further examinedand also showed significant increase in 3G4 binding as compared withuntreated cells.

Human breast cancer MDA-MB-231 cells were treated with 10 nM ofdocetaxel for 24 hrs and incubated with either the chimeric 3G4 antibody(ch3G4) or control, human IgG and analyzed by FACS. These results showthat the significant increase in antibody binding is antigen-specificand that the chimeric antibody behaves like the parent 3G4 antibody(FIG. 26).

D. Synergistic Tumor Treatment with 3G4 and Docetaxel

The inventors have thus shown that the treatment of endothelial cellsand tumor cells with docetaxel at subclinical concentrationsignificantly increases 3G4 binding. They have also shown that the 3G4antibody facilitates macrophage-mediated phagocytosis of tumor cells onwhich PS is exposed at the surface. The increased 3G4 binding mediatedby docetaxel should therefore augment the phagocytosis of tumor cellsand other anti-tumor effects mediated by the Fc domain of the 3G4antibody, such as increasing the lytic activity of NK cells, leading tomore effective ADCC. Studies of others have also shown that treatment ofbreast cancer patients with docetaxel leads to an increase in serumIFN-γ, IL-2, IL-6 and GM-CSF cytokine levels and enhancement of NK andLAK cell activity (Tsavaris et al., 2002).

The anti-tumor effect of the combined therapy of 3G4 with docetaxel wastherefore examined in an orthotopic model in SCID mice bearing humanMDA-MB-435 breast carcinoma. Mice bearing orthotopic MDA-MB-435 humanbreast tumor were treated i.p. with 3G4 alone (100 μg/dose), docetaxelalone (10 mg/kg), or 3G4 in combination with docetaxel (100 μg/dose and10 mg/kg, respectively), for three weeks, with administration 3 times aweek. Treatment started 6 days after tumor cell implantation.

These studies showed that the combined therapy of 3G4 plus docetaxelresulted in growth inhibition of 90%. Growth inhibition of 3G4 plusdocetaxel was significantly superior to 3G4 alone (p<0.005) anddocetaxel alone (p<0.01).

E. 3G4-Targeting of Apoptotic Tumor Cells to FcγR on Dendritic Cells

Tumors from mice treated with 3G4 plus docetaxel also contained unusualamount of lymphocytes, as compared to control tumors. Although thisphenomenon could represent typical chemoattraction of immune cells bydisintegrating tumor cells, it could also reflect activation of theimmune system by 3G4 mediated through Fc binding to FcγR on immuneeffector cells.

To characterize the effects of 3G4 and docetaxel administration on theintratumoral immune cell infiltrate, the types of cells present in theseinfiltrates can be identified by immunostaining of frozen sectionsand/or paraffin sections of tumor tissues using antibodies directedagainst specific markers of macrophages, neutrophils, granulocytes, NKcells and activated lymphocytes (Pharmingen, San Diego, Calif.). Theextent, phenotype, and activation status of this infiltrate can begraded. Cytokine production by infiltrating immune cells, including IL-2and INF, can also be analyzed via immunohistochemical techniques. Serumcytokine levels can be evaluated by ELISA and intracellular staining canbe used to identify the specific cellular compartments responsible forcytokine production. The effects of infiltrating immune cells on tumorcell proliferation and apoptosis can thus be systematically evaluated.

In light of the foregoing data, the inventors further contemplatemethods enhancing the potency of immunotherapy of breast cancer by3G4-mediated targeting of apoptotic tumor cells to the Fc gamma receptor(Fc(γ)R) on dendritic cells. Efficient antigen presentation, whichinduces effective cellular and humoral immune responses, is importantfor the development of tumor vaccines and immunotherapies. Dendriticcells (DC) are the most potent antigen-presenting cells (APC) that primecytotoxic T lymphocytes against tumor-associated antigens. Improvementof tumor antigen presentation by dendritic cells (DCs) should lead todevelop more potent tumor vaccines.

Antigenic presentation by Fc(γ)R receptor-mediated internalization ofDCs can be enhanced up to 1,000-fold compared with fluid phase antigenpinocytosis. Apoptotic tumor cells (ATC) are an excellent source ofantigens for dendritic cell loading because multiple tumor specificantigens (both known and unknown) can be efficiently presented to naïveT cells, making the occurrence of immune escape variants less likely dueto the lock of certain epitopes. In animal studies, DCs pulsed with ATCshave been shown to produce potent anti-tumor immunity in vitro and invivo. However, recent data has demonstrated that ATCs alone weresomewhat inefficient for activating anti-tumor immunity, possiblybecause of their insufficient uptake and inability to induce DCmaturation.

Recent studies have also demonstrated that ATC-immune complex, formed bybinding of anti-tumor antibody to apoptotic tumor cells, can be targetedto Fc(γ)R on DC. Compared with ATCs alone, ATC-immune complexes weremore efficiently internalized by DC, more efficient in inducing DCactivation and maturation, and more importantly, ATC-immune complexescan significantly enhance both MHC I and II-restricted antigenpresentation, therefore induce potent anti-tumor T helper and CTLimmunity.

The inventors therefore envision using the anti-PS antibodies of thepresent invention to enhance both hormonal and cellular anti-tumorimmunity, and boost the efficacy of ATC based DC tumor vaccines. As PSis a universal and the most abundant specific marker of apoptotic tumorcells, the panel of antibodies of the invention, particularly 3G4, canbind to PS on ATCs. The inventors have already demonstrated that 3G4 canenhance DC uptake of apoptotic tumor cells by 300% through Fc(γ)Rmediated internalization of 3G4-ATC complexes. By enhancing the uptakeof ATC by DC mediated through Fc(γ)R, it is therefore reasoned that 3G4and like antibodies can greatly enhance both MHC I and II restrictedantigen presentation, induce both potent hormonal and cellularanti-tumor immunity, and boost the efficacy of ATC based DC tumorvaccines. This can be demonstrated by establishing the efficacy of DCloaded with 3G4-ATC immune complexes in the induction of T h1, CTL andantibody response in vivo, and by determining the potency of anti-tumorimmunity induced by immunization of DC loaded with 3G4-ATC immunecomplexes in vivo.

Example XXI Anti-PS Antibodies Treat CMV Infections In Vivo

Following the anti-viral effects against CMV in vitro shown in ExampleXII, the present example demonstrates the enhanced survival of miceinfected with the murine version of the CMV virus, mCMV.

Balb/C mice (6 week old, five mice per group) were infected i.p. with5×10⁵ pfu of mCMV RVG102. The mice were treated i.p. on day 1 with the3G4 antibody (1 mg/mouse), or the human-mouse chimeric antibody, ch3G4described above (1 mg/mouse). Untreated mice served as the control. Themice were treated every four days thereafter with 0.5 mg/mouse ofantibody or chimeric antibody until day 26. The mice were monitored forsurvival past 90 days post infection.

Treatment with both the parent and chimeric forms of the 3G4 antibodyresulted in increased survival of the mCMV-infected mice. Mice, treatedwith 3G4 or ch3G4 had 100% and 80% survival, respectively, as comparedto untreated mice, wherein only 25% of the mice survived the infection(FIG. 27).

Example XXII PE-Binding Peptide Derivative Treats CMV Infection In Vivo

In addition to the in vitro anti-viral effects against CMV shown inExample XVII, this example demonstrates that the duramycin-biotinderivative, DLB increased survival of mice infected with mCMV.

Balb/C mice (6 week old, five mice per group) were infected i.p. with5×10⁵ pfu of mCMV RVG102. The mice were treated i.p. on day 1 and everyfour days with 20 μg/mouse of the duramycin derivative, DLB. Untreatedmice served as the control. The mice were monitored for survival past 90days post infection.

Treatment with the duramycin-biotin derivative, DLB enhanced survival ofthe mCMV-infected mice. Mice treated with DLB had 100% survival, ascompared to untreated mice, wherein only 25% of the mice survived theinfection (FIG. 28).

Example XXIII Anti-PS Antibodies Bind to Virally Infected Cells

The present example shows that viral infection induces PS exposure atthe cell surface and that anti-PS antibodies bind to virally infectedcells. Cells infected with Vaccinia virus become PS-positive, as shownby increased binding of the chimeric 3G4 antibody to the cell surfacedemonstrated in FACS analyses.

U937 cells were infected with trypsinized Vaccinia virus at a high m.o.iof 2. Briefly, Vaccinia virus was treated with an equal volume of 0.25mg/ml trypsin for 30 minutes at 37° C. The virus was added to U937 cellsin a total volume of 0.5 ml. After 1.5 hr, fresh medium was added to thecells and the cells were incubated in a T25 flask at 37° C. for 2 days.Uninfected cells served as the controls.

Infected and uninfected U937 cells were stained with a primary antibody,either with the chimeric 3G4 antibody (ch3G4) or with human IgG (HIgG)as a control. The cells were washed, blocked with normal mouse serum andthen stained with the primary antibody for 45 minutes on ice. Afterthree washes, the cells were stained with a 1:400 dilution of goatanti-human FITC-conjugated secondary antibody and were analyzed on aFACScan.

Results from the FACS analyses show that there is a significant shiftwith ch3G4 on U-937 cells infected with Vaccinia virus (FIG. 29B, right(green) peak), as compared to that obtained on uninfected U937 cells(FIG. 29A, right (green) peak). This study therefore shows thatinfection of cells with Vaccinia virus leads to PS exposure on the cellsurface and that the chimeric version of the anti-PS antibody, 3G4 iscapable of binding to these virally infected cells.

Example XXIV Anti-Viral Effects of Anti-PS Antibodies Against PichindeVirus

In addition to the anti-viral effects against CMV and RSV, the presentexample further shows that anti-PS antibodies inhibit Pichinde virusinfection in vitro. Pichinde virus is New World arenavirus, which isnon-pathogenic in man, and is used in an animal model for Lassa fever.

Confluent monolayers of Vero cells were treated with the 3G4 antibody oran isotype-matched control antibody, GV39G, after infection withPichinde virus at a low m.o.i. of 0.01 pfu/cell. Briefly, the cells wereincubated with virus in a total volume of 1 ml per well at 37° C. for 90minutes. During the infection, the plates were gently rocked every 30minutes. Following the infection, the cell supernatant was removed andDMEM/10% FBS/pen-strep was added to each well (2 ml per well). On day 2,the cells were harvested with trypsin and allowed to adhere to Biocoatchamber slides. They were fixed and stained with polyclonal rabbitanti-PIC serum followed by a biotin-conjugated goat anti-rabbitsecondary (secondary antibody alone produced no staining, as shown inFIG. 30C). The number of infected cells per field of 100 cells wascounted.

In cells treated with 3G4, the virus is restricted to single cells thatstain a dark red, numbering about one in about a hundred cells (FIG.30A). These are probably the cells that were originally infected by thevirus, as was seen with CMV (Example XII). However, in cells treatedwith the control, GV39G antibody, the virus has spread and infected allthe cells (FIG. 30B).

This pattern of inhibition of viral replication is similar to thatobserved when 3G4 was used to treat CMV-infected human fibroblasts.Thus, the anti-PS antibody, 3G4 effectively prevents the spread ofPichinde virus from cell to cell, as quantified in FIG. 30D.

Example XXV Tumor Treatment Using PE-Binding Peptide Derivative

Further to the anti-viral effects of duramycin derivatives, both invitro and in vivo, the present example demonstrates the localization ofduramycin derivatives to tumor vasculature and associated anti-tumoreffects.

A. Tumor Treatment with Duramycin-HuIgG Conjugate

Human IgG (HIgG) was first purified as described in Example XV. PurifiedHIgG was linked to duramycin using the SIAB linker, and the resultant(D-SIAB)_(n)HIgG conjugate purified.

Mouse fibrosarcoma cell-line MethA was grown, harvested at log phase andresuspended in DPBS. Approximately 10⁶ MethA tumor cells were injectedsubcutaneously in the middle dorsum of 6-8 week old BALB/c male mice. 5days after implantation, the mice were randomly separated into twogroups (n=15). From day 10, one group received 150 μg Duramycin-HuIgGconjugate by intraperitoneal injection for consecutive 2 weeks. Theother group received the same amount of HuIgG as a control. Tumorvolumes were measured twice a week and were calculated using the formula½ab², (where “a” is the long axis and “b” the short axis of the tumor).Mice were sacrificed when the tumors reached a size of approximately1400 mm³.

The duramycin-HIgG conjugate inhibited MethA tumor growth in BALB/c miceat the dose of 150 μg/day, as compared to the human IgG control (FIG.31).

B. Duramycin-HuIgG Conjugate Localizes to Tumor Vasculature

Using the same MethA mouse tumor model as above, when the tumor sizereach 500 mm³, 100 μg (D-SIAB)_(n)HIgG in 100 μl PBS was injectedthrough the tail vein. The same amount of human IgG was injected as acontrol. After 4 hours, mice was euthanized and perfused with normalsaline for 5 minutes and 1% paraformadehyde for 10 minutes. The tumorand other major organs were dissected and frozen in liquid nitrogen.After embedding in OCT, tissue was cryosected in 10 μm section andplaced on silanized slides. After fixing in cold acetone for 10 minutes,slides were stained with peroxidase labeled goat anti human IgG todetect the biodistribution of duramycin-HuIgG. Meca32 and peroxidaselabeled goat anti-rat IgG were used to detect blood vasculature oftissue.

This study showed that the duramycin-HIgG conjugate localized to thetumor vasculature in the treated animals.

Example XXVI Biodistribution and Properties of Duramycin Conjugates

The present example demonstrates the lack of toxicity of cell-impermeantduramycin derivatives in vitro, the biodistribution of duramycinderivatives administered in vivo and the ability of duramycin-antibodyconjugates to increase the phagocytosis of apoptotic cells bymacrophages.

A. Duramycin-Biotin Conjugates are not Cytotoxic

The duramycin derivatives and conjugates of the invention are designedto minimize the non-specific toxic effects of the parent duramycinmolecule. In many examples, this is achieved by linking duramycin to acell impermeant group (Example XV).

The biotinylated duramycin construct DLB was prepared as described inExample XV. The unmodified duramycin compound and DLB were tested forcytotoxic effects on HUVEC using an MTT assay. Whilst the unmodifiedduramycin showed dose-dependent toxicity, DLB was non-toxic, matchingthe untreated control (FIG. 32).

B. Localization of Duramycin-Biotin Conjugate to Macrophages in Lung

The human breast cancer cell line MDA-MB-435 was grown, harvested at logphase, and resuspended in DPBS. Approximately 10⁷ cells were injectedinto the mammary fat pad of 6-8 week old female ethylic nude mice. 100μg duramycin-biotin in 100 μl PBS was injected through the tail vein.After 4 hours, mice was euthanized and perfused with normal saline for 5minutes and 1% paraformadehyde for 10 minutes. Major organs, includingheart, lung, liver, kidney, brain, intestine, testes and spleen weredissected and frozen in liquid nitrogen. After embedding in OCT, tissuewas cryosected in 10 μm sections and placed on silanized slides. Afterfixing in cold acetone for 10 minutes, slides were stained with Cy3labeled streptavidin to detect the biodistribution of theduramycin-biotin construct. Meca32 and FITC labeled goat anti rat IgGwere used to detect blood vasculature of tissue.

The intravenous injection of the duramycin-biotin conjugate into nudemice bearing MDA-MB-435 tumors resulted in the deposition of drug in thetumor cells, renal tubules and in the macrophages in the lung. There wasminimal deposition in liver and no detectable distribution in brain,intestine, testes. The localization to macrophages in the lung can beexploited in the anti-viral embodiments of the invention.

C. Duramycin-Antibody Conjugate Enhances Phagocytosis of Apoptotic Cells

The ability of a duramycin-antibody conjugate (duramycin-C44, DuC44) toincrease the phagocytosis of apoptotic cells was next investigated.

Macrophages were isolated and cultured from mouse bone marrow. Themedium used for the isolation, culture, and stimulation of BMmacrophages was DMEM containing 2 mM glutamine, 0.37% (w/v) NaHCO₃, 10%(v/v) heat-inactivated FCS, and 0.5 ng/ml mouse GM-CSF. Bone marrowcells were flushed asceptically from the dissected femurs with jet ofcomplete medium directed through a 25-gauge needle. The cells were thenadjusted to a density of approximately 3×10⁵ cells/ml of completemedium, and were distributed in 0.5 ml aliquots into 8 well chamberslides.

Cells were incubated for 1 hour at 37° C. in 5% CO₂, in a humidifiedchamber to allow macrophages to adhere and spread. Nonadherent cellswere removed by adding 5 ml of warmed PBS to each well, resuspendingnonadherent cells by moderately tapping the plate, and flicking theslides to discard the nonadherent cells. This washing was performed atotal of three times. The cells were maintained at 37° C. under a 7.5%(v/v) CO₂ atmosphere for 5 days. The complete medium was changed everyother day until the cells were used.

The following method was used to label HL-60 target cells with afluorescent cell tracer. A 10 mM CFDA SE stock solution was preparedimmediately prior to use by dissolving the contents of one vial dye in90 μL of the DMSO and diluting in PBS to 10 μM. Centrifugation was usedto obtain a HL-60 cell pellet and the supernatant aspirated. The cellswere resuspend in CFDA/PBS and incubated at 37° C. for 15 minutes. Thesamples was centrifuged and the supernatant aspirated. The cells wereresuspend in media and incubated for another 30 minutes. The cellviability and fluorescence were confirmed to be over 95%.

In this phagocytosis assay, labeled HL-60 cells were exposed to UV 254nm for 5 minutes and incubated at 37° C. for one hour to induceapoptosis. 10⁴ apoptotic HL-60 cells were incubated with macrophages forone hour. Duramycin-C44 conjugate was included at the concentration of10 μg/ml. The same concentration of mouse antibody BBG3 was used as anegative control, and the 3G4 antibody was also included for comparison.Hoechst 33342 was added in media in the last 45 minutes at theconcentration of 10 μg/ml.

Slides were washed with PBS 3 times, and fixed in 4% paraformadehyde for15 minutes. The slides were stained with rat anti-mouse CD11 antibody(CD11 is a macrophage marker), diluted in 0.2% gelatin for one hour,washed and stained with Texas red labeled goat anti-rat secondaryantibody.

The cells were analyzed under the fluorescence microscope. Macrophagesare identified as red cells, due to the CD11 marker. Macrophages thathave phagocytosed apoptotic cells are identified as green cells, due tothe fluorescent tracer in the target cells. Red and green cells arecounted and the phagocytosis is quantified as the percent phagocytespositive for uptake.

This study shows that the duramycin-antibody conjugate, DuC44 enhancedphagocytosis of apoptotic HL-60 cells by macrophages (FIG. 33). Thus,the duramycin portion is binding to the surface of the apoptotic cells,permitting the protruding antibody portion of the conjugate to berecognized by the macrophages. The duramycin-antibody conjugate thusfunctioned similarly to the 3G4 antibody. As expected, an (Fab)₂fragment of the 3G4 antibody, lacking the Fc region, did not inducephagocytosis above control levels.

As the earlier study showed duramycin-biotin conjugates to localize tomacrophages in the lung following administration in vivo, thestimulation of macrophage-mediated phagocytosis of apoptotic cells shownin the present study has important implications for the therapeutic usesof the present invention, such as in treating pulmonary viralinfections.

All of the compositions and methods disclosed and claimed herein can bemade and executed without undue experimentation in light of the presentdisclosure. While the compositions and methods of this invention havebeen described in terms of preferred embodiments, it will be apparent tothose of skill in the art that variations may be applied to thecompositions and methods and in the steps or in the sequence of steps ofthe method described herein without departing from the concept, spiritand scope of the invention. More specifically, it will be apparent thatcertain agents which are both chemically and physiologically related maybe substituted for the agents described herein while the same or similarresults would be achieved. All such similar substitutes andmodifications apparent to those skilled in the art are deemed to bewithin the spirit, scope and concept of the invention as defined by theappended claims.

REFERENCES

The following references, to the extent that they provide exemplaryprocedural or other details supplementary to those set forth herein, arespecifically incorporated herein by reference.

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1. A method for treating an animal with cancer, comprising administeringto said animal a therapeutically effective amount of a first anti-canceragent, wherein said first anti-cancer agent is an immunoconjugatecomprising at least a first therapeutic agent operatively attached to anantibody, or antigen-binding fragment thereof; wherein said antibody orantigen-binding fragment thereof comprises at least two variable regionsthat each comprises three CDRs, wherein said two variable regions are:(a) a heavy chain variable region that comprises variable heavy (VH)CDR1, VH CDR2 and VH CDR3 from the monoclonal antibody 3G4, produced byhybridoma ATCC PTA 4545, wherein said VH CDR1 has the amino acidsequence of SEQ ID NO:10, said VH CDR2 has the amino acid sequence ofSEQ ID NO:11 and said VH CDR3 has the amino acid sequence of SEQ IDNO:12; and (b) a light chain variable region that comprises a variablelight (VL) CDR1, VL CDR2 and VL CDR3 from the monoclonal antibody 3G4,produced by hybridoma ATCC PTA 4545, wherein said VL CDR1 has the aminoacid sequence of SEQ ID NO:13, said VL CDR2 has the amino acid sequenceof SEQ ID NO:14 and said VL CDR3 has the amino acid sequence of SEQ IDNO:15.
 2. The method of claim 1, further comprising administering tosaid animal a therapeutically effective amount of at least a secondanti-cancer agent.
 3. The method of claim 2, wherein said at least asecond anti-cancer agent is a chemotherapeutic agent, radiotherapeuticagent, anti-angiogenic agent or apoptosis-inducing agent.
 4. The methodof claim 1, further comprising subjecting said animal to surgery orradiotherapy.
 5. The method of claim 1, wherein said immunoconjugatebinds to the luminal surface of blood vessels of the vascularized tumor.6. The method of claim 1, wherein said immunoconjugate comprises atleast a first chemotherapeutic agent, radiotherapeutic agent,anti-angiogenic agent, apoptosis-inducing agent, anticellular agent,cytotoxin, steroid, antimetabolite, anthracycline, vinca alkaloid,anti-tubulin drug, antibiotic, cytokine, chemokine, coagulant oralkylating agent.
 7. The method of claim 6, wherein said immunoconjugatecomprises a chemotherapeutic agent listed in Table E or Table F.
 8. Themethod of claim 6, wherein said immunoconjugate comprises daunorubicin,doxorubicin, adriamycin, etoposide, actinomycin-D, paclitaxol,colchicine, taxol, vinblastine, vincristine, vindescine, acombretastatin or docetaxel.
 9. The method of claim 6, wherein saidimmunoconjugate comprises an anti-angiogenic agent listed in Table B.10. The method of claim 6, wherein said immunoconjugate comprises aplant-, fungus- or bacteria-derived toxin.
 11. The method of claim 10,wherein said immunoconjugate comprises an A chain toxin, ricin A chain,deglycosylated ricin A chain, a ribosome inactivating protein, α-sarcin,gelonin, aspergillin, restrictocin, a ribonuclease, anepipodophyllotoxin, diphtheria toxin or Pseudomonas exotoxin.
 12. Themethod of claim 11, wherein said immunoconjugate comprises gelonin. 13.The method of claim 6, wherein said immunoconjugate comprises thecytokine, interleukin-12, interleukin-2 or interferon-α; or thechemokine, LEC.
 14. The method of claim 6, wherein said immunoconjugatecomprises TNFα.
 15. The method of claim 6, wherein said immunoconjugatecomprises a coagulant.
 16. The method of claim 1, wherein said animal isa human patient.
 17. The method of claim 1, wherein said immunoconjugatecomprises therapeutic agents operatively attached to said antibody, orantigen-binding fragment thereof.
 18. The method of claim 1, whereinsaid immunoconjugate comprises an antibody, or antigen-binding fragmentthereof, that comprises a heavy chain variable region having the aminoacid sequence of SEQ ID NO:2.
 19. The method of claim 1, wherein saidimmunoconjugate comprises an antibody, or antigen-binding fragmentthereof, that comprises a light chain variable region having the aminoacid sequence of SEQ ID NO:4.
 20. The method of claim 1, wherein saidimmunoconjugate comprises an antibody, or antigen-binding fragmentthereof, that comprises a heavy chain variable region having the aminoacid sequence of SEQ ID NO:2 and a light chain variable region havingthe amino acid sequence of SEQ ID NO:4.
 21. The method of claim 1,wherein said immunoconjugate comprises said antigen-binding fragment ofsaid antibody operatively attached to a human antibody constant region.22. A method for treating an animal with cancer, comprisingadministering to said animal a therapeutically effective amount of afirst anti-cancer agent, wherein said first anti-cancer agent is animmunoconjugate comprising at least a first therapeutic agentoperatively attached to an antibody; wherein said antibody comprises atleast two variable regions that each comprises three CDRs, wherein saidtwo variable regions are: (a) a heavy chain variable region thatcomprises variable heavy (VH) CDR1, VH CDR2 and VH CDR3 from themonoclonal antibody 3G4, produced by hybridoma ATCC PTA 4545, whereinsaid VH CDR1 has the amino acid sequence of SEQ ID NO:10, said VH CDR2has the amino acid sequence of SEQ ID NO:11 and said VH CDR3 has theamino acid sequence of SEQ ID NO:12; and (b) a light chain variableregion that comprises a variable light (VL) CDR1, VL CDR2 and VL CDR3from the monoclonal antibody 3G4, produced by hybridoma ATCC PTA 4545,wherein said VL CDR1 has the amino acid sequence of SEQ ID NO:13, saidVL CDR2 has the amino acid sequence of SEQ ID NO:14 and said VL CDR3 hasthe amino acid sequence of SEQ ID NO:15.
 23. The method of claim 22,wherein said immunoconjugate comprises an antibody that comprises aheavy chain variable region having the amino acid sequence of SEQ IDNO:2.
 24. The method of claim 22, wherein said immunoconjugate comprisesan antibody that comprises a light chain variable region having theamino acid sequence of SEQ ID NO:4.
 25. The method of claim 22, whereinsaid immunoconjugate comprises an antibody that comprises a heavy chainvariable region having the amino acid sequence of SEQ ID NO:2 and alight chain variable region having the amino acid sequence of SEQ IDNO:4.
 26. The method of claim 22, further comprising administering tosaid animal a therapeutically effective amount of at least a secondanti-cancer agent.
 27. A method for treating an animal with cancer,comprising administering to said animal a therapeutically effectiveamount of a first anti-cancer agent, wherein said first anti-canceragent is an immunoconjugate comprising at least a first therapeuticagent operatively attached to an antibody, or antigen-binding fragmentthereof; wherein said antibody or antigen-binding fragment thereofcomprises at least two variable regions that each comprises three CDRs,wherein at least one of said variable regions is: (a) a heavy chainvariable region from the monoclonal antibody 3G4, produced by hybridomaATCC PTA 4545, which has the amino acid sequence of SEQ ID NO:2; or (b)a light chain variable region from the monoclonal antibody 3G4, producedby hybridoma ATCC PTA 4545, which has the amino acid sequence of SEQ IDNO:4.
 28. The method of claim 27, further comprising administering tosaid animal a therapeutically effective amount of at least a secondanti-cancer agent.
 29. A method for treating an animal with cancer,comprising administering to said animal a therapeutically effectiveamount of a first anti-cancer agent, wherein said first anti-canceragent is an immunoconjugate comprising at least a first therapeuticagent operatively attached to monoclonal antibody 3G4, produced byhybridoma ATCC PTA 4545, or an antigen-binding fragment thereof.
 30. Themethod of claim 29, wherein said immunoconjugate comprises at least afirst chemotherapeutic agent, radiotherapeutic agent, anti-angiogenicagent, apoptosis-inducing agent, anticellular agent, cytotoxin, steroid,antimetabolite, anthracycline, vinca alkaloid, anti-tubulin drug,antibiotic, cytokine, chemokine or alkylating agent.
 31. The method ofclaim 30, wherein said immunoconjugate comprises daunorubicin,doxorubicin, adriamycin, etoposide, actinomycin-D, paclitaxol,colchicine, taxol, vinblastine, vincristine, vindescine, acombretastatin or docetaxel.
 32. The method of claim 30, wherein saidimmunoconjugate comprises a plant-, fungus- or bacteria-derived toxin.33. The method of claim 32, wherein said immunoconjugate comprises an Achain toxin, ricin A chain, deglycosylated ricin A chain, a ribosomeinactivating protein, α-sarcin, gelonin, aspergillin, restrictocin, aribonuclease, an epipodophyllotoxin, diphtheria toxin or Pseudomonasexotoxin.
 34. The method of claim 30, wherein said immunoconjugatecomprises interleukin-12, interleukin-2, tumor necrosis factor-α,interferon-α or liver-expressed chemokine (LEG).
 35. The method of claim29, wherein said immunoconjugate comprises a coagulant.
 36. The methodof claim 29, wherein said animal is a human patient.
 37. The method ofclaim 29, further comprising administering to said animal atherapeutically effective amount of at least a second anti-cancer agent.38. The method of claim 37, wherein said at least a second anti-canceragent is a chemotherapeutic agent, radiotherapeutic agent,anti-angiogenic agent or apoptosis-inducing agent.
 39. The method ofclaim 29, further comprising subjecting said animal to surgery orradiotherapy.
 40. The method of claim 29, wherein said immunoconjugatecomprises said monoclonal antibody 3G4 produced by hybridoma ATCC PTA4545.
 41. The method of claim 29, wherein said immunoconjugate comprisessaid antigen-binding fragment of said monoclonal antibody 3G4 producedby hybridoma ATCC PTA
 4545. 42. The method of claim 41, wherein saidantigen-binding fragment of said monoclonal antibody 3G4, produced byhybridoma ATCC PTA 4545, is operatively attached to a human antibodyconstant region.
 43. A method for treating an animal with cancer,comprising administering to said animal a therapeutically effectiveamount of an immunoconjugate comprising at least a first therapeuticagent operatively attached to monoclonal antibody 3G4, produced byhybridoma ATCC PTA 4545.